If your friends want they can also listen to our faction episodes on Adeptus Podcastus. In each one I discuss the lore for that week's faction. 

It would, indeed, be helpful if it were more clear if your friends are more interested in descriptions of how the factions play, or what the factions are in the 40K universe.  Since you're talking about how your friends know nothing of 40K in the first place, I get the impression that you're looking for a description of what the factions are in context of the universe.  That, and Wytefang has already done a pretty good job of aptly summarizing general playstyle we can draw from the existing card pool.  Unfortunately, there isn't really much in the way of what you're looking for, even on GW's website they don't really have what you're looking for as far as I know, their website tends to go straight into selling you miniatures bereft of context.  Lexicanum might help you, but it's not exactly brief.  I am reminded of what Sten says in Dragon Age: Origins when asked to describe his people, "People are not simple.  They cannot simply be generalized in the manner of, 'Elves are a lithe, pointy-eared people who excel at poverty.'"  That aside, I'll give it my best shot to summarize the factions in Conquest within the 40K universe with as little required leaning on historical or in-depth lore knowledge as possible... it kind of defeats the purpose of a faction description if they have to go to some other external source to understand key elements within it.
 
Space Marines - Genetically-enhanced super-soldiers, to the point that it is a very fair argument as to whether or not they are still truly human, and equipped with the best of its armor and weaponry, they are considered Mankind's greatest elite warriors, answerable to almost none other than their own.  They are, however, few in number and thus used as a scalpel rather than a sledgehammer, specializing in surgical strikes, special operations, or other tasks that simply could not be trusted to lesser soldiers.  They often strike from the skies in shocking attacks, relying on their superhuman capabilities and their advanced use of tactics to carry them to victory.
 
Astra Militarum - The true army of Mankind, composed of the great masses of common humanity.  Physically inferior and underequipped in comparison to almost every enemy they will ever face, they still come through thanks to their vast numbers, their unyielding determination, and effective use of combined arms.  The life of Guardsmen is often short, notable for its misery, hopelessness, and great sacrifice.  Few can dig in and hold the line from a supported, fortified position like the Astra Militarum, ready to greet the enemies of Man with a vast gunline, a wall of armored tank steel, and a thundering artillery barrage, and a determination to never give up no matter how grim the odds.
 
Orkz - A very old, very chaotic species that is spread throughout the whole galaxy, Orkz live for nothing but war.  To an Ork, the idea of peace is as horrifying as war would be to a human, for it is in war that the Ork society finds purpose, and those that survive grow bigger and stronger from their experiences, and thus more important in their society.  Orkz are brutal and barbaric, caring only for brute strength as a leadership quality, and often not having the capacity to think of tactics more advanced than rushing headlong at the enemy.  Their technology is ramshackle, primitive, salvaged and cobbled-together, and often literally only maintained by the Ork belief that it will work.  To be an Ork is a simple, pure existence, you fight because you were made for fighting and winning.
 
Chaos - Chaos refers both to the daemons and Dark Gods of the Warp, a dimension beyond our own created by sentient emotions, and to the human followers of the same.  From Chaos come the daemons from Mankind's darkest nightmares, created from the darkest parts of their own emotions, and those Space Marines and humans that have turned their backs on humanity to join them, which can be for reasons beyond counting.  Their motivations, likewise, can vary greatly, but the one thing that tends to unite all of them in their inevitable insanity is a yearning desire to see Mankind's Imperium burn, and tear down everything humanity has managed to build.  With the aid of immortal, inhuman daemons and dark warp sorceries, it is far from impossible they may achieve their aim.
 
Dark Eldar - The last true remnants of the ancient Eldar Empire that preceded humanity, the Dark Eldar are those that cling to the same degenerate ways and practices that caused the fall of their Empire in the first place.  Now very few in number and reduced to hiding in a twilight realm between the material world and the Warp, they exist only to bring pain and suffering to others, ostensibly for their own amusement.  Utilizing the most powerful and depraved technologies of the Eldar Empire with no regard for morality to contain them, they strike from the shadows in lightning raids to carry off other sentient species to their twilight realm, purely so that they may sadistically torture them for as long as is possible.  Their military strategy is focused around being as light and fast as possible, sacrificing armor for maneuverability and speed wherever possible.  The Dark Eldar are likely the closest thing to pure evil in the setting, living only for their wretched excesses and depraved sadistic desires, and it is best to pray they do not take you alive.
 
Eldar - Very few in number, the Eldar are those who foresaw the coming destruction of the Eldar Empire and fled on vast Craftworlds beforehand, seeking to change their ways and avoid making the mistakes of their fallen kin.  They now seek to live lives of rigid discipline, moderation, and training.  Few can read the skeins of fate and foretell the future as well as these Eldar, and they tend to only interact with the galaxy towards the end of manipulating the future to their benefit, often looking to forestall disasters.  However, as these disasters may be decades, centuries, or even millennia in the future to come, the actions of the mysterious Eldar can often seem random and purposeless at best to outsiders, making them a very mysterious race to others.  They make use of powerful technology as well as some of the most potent psychic power of any race in the galaxy to accomplish their goals.  While not truly evil, the Eldar have little regard for any race that is not their own and will do anything to survive.
 
Tau - A young and ambitious race that has only just ventured out into the broader galaxy, but has already made a substantial impression.  The Tau are a rationally-minded, scientific, technologically-advanced race that is almost completely united and driven by its communitarian philosophy of the "Greater Good", a revelation they seek to share and spread to all the rest of the galaxy as they incorporate more into their small but growing Empire.  Despite having an overly optimistic, indeed naive view of the galaxy they are in, the Tau have done better than most at mastering its challenges.  The Tau have some of the most incredibly advanced technology of any race in the galaxy, and they only seek to improve it further, but they do have no psychic potential or any true understanding of the Warp.  The Tau are also notable for being entirely oriented around firepower and long-ranged fighting, considering close-ranged engagements barbaric and distasteful.  Despite lacking the sheer numbers of humanity, Orkz or the Tyranids, Tau often make up for it with their very rational, pragmatic understanding of tactics and their highly-advanced technology that often gives them a major firepower advantage.

Addition to number 3; you can also trap a mobile unit on the Last planet.
Some of my own misplays:
Don't assume that just because you have Initiative this turn that you'll have it in the Combat phase - if the enemy Warlord shows up to the party and yours didn't, you've forfeited your right to Initiative for this combat. Particularly important on the First planet.
And related:
Don't always assume your opponent is interested in capping the First planet this round. More than once I've attempted to ensure initiative by sending my Warlord in on turns when I have the token, only for my opponent to commit elsewhere - not only have I wasted my Warlord by sending him to a planet where he wasn't needed, I've dragged all the guys in HQ with him - and now they're stuck returning to HQ again at the end of this turn.

I suspect it's an elaborate hoax and the game doesn't exist.
 
Somewhere, deep in the bowls of Fantasy Flight games about a week before GenCon, one of the LCG designers laying sprawled on a sofa, surrounded by mountains of beer bottles and empty pizza boxes slurs at the other two men laying the deepening gloom "Hey guys. Guise. Wherent weee suhpossed to do something..."
 
The two other developers barely stir, but a barely clothed woman pushes the pizza awakens and starts to brush off the Netrunner credit tokens that had been thrown her way the night before, the ominous words "I run on your Archive" bouncing backward and forward in her brain, itself still cloudy from hours previously where they'd all decided that it was a good idea to start bringing back the Greyjoy discard theme.
 
"Oh... ohgohd... We we were supposed to design the Conquest LCG" He looked up in horror at a close-by computer screen, the Conquest page uploaded prematurely by one of them, doubtless as a drunken dare. The public knew it existed. They'd have to pull it all together and produce it, but the only work they'd done so far was to scrawl "Slanesh's arse 3x in Core" on the wall.
 
As great as that was, it just wasn't enough.
 
---
 
I'm too tired to continue this now. Maybe later.

When the delivery date is the end of the month like that, it usually indicates the information the store got from the company or their distributor was "in September," as opposed to "on September 29." That's why you'll often see pre-order release dates on retailer sites jump a month at a time.

The place I pre-ordered from has had a tentative delivery date of Sep 29/Oct 1 for a couple of weeks now. I was assuming that they had a pretty good idea already. But I'm starting to doubt it, since here we are, mid-September and still shows on the boat. I don't see how they can make it. My only hope is that, as has happened before, FFG is slow to update when things come off the boat and next thing you know it is released. Unfortunately, it sounds like Oct 9 is a more realistic date. It is frustrating, I mean people are putting up threads on common misplays and I haven't even had a chance to play a real game yet.

And currently there's no way to deploy a unit directly to HQ from hand I believe (outside the planet battle ability). Though always room in the design space for that to change I guess.

No, they move with the warlord when the warlord commits to a planet.

And unlike the Warlord arrive Exhausted.

Each faction can be mono, allied with left neighbour, or allied with right neighbour. Eventually someone will start ranking all 21 options (and aggregating and averaging people's rankings), shifting them up/down with each expansion pack!!

lore is not really something I care about, I love the 40K lore, but the responsibility of the designers is in mechanism and gameplay imo. GW used to be all about user creation, in fact in the early days it was more like a RPG. Everyone made their own chapters and heroes and stuff. This was when 40K ruled the most. Nowadays so much of the imagination is gone.
As for adding lore, the most famous made up one is Blood Ravens. A completely made up chapter by a computer game company, with its own heroes and villains and chapter with its own histories. People completely accepted it and loved it, in fact I have seen my mate freak out at conventions when people ask about his blood raven army (he plays blood angels)
FFG has a tradition of putting little short stories in their expansion packs. if I was involved I would have each packs sheet contain a full bio of the hero as well as some history about him and his place in the universe. This would be a perfect place to do this and allow them to really get into the meat of the history of THIS game. Make up their own stuff and add to the lore for a change.
I rag on Star Wars a lot but I do love how themed the expansions packs were, you can look at them and they in fact tell a story, as do the cards they contain. I thought this was pretty awesome and it is what I hope they do in this game.

Creating new warlords is walking a thin line for alot of people. They can do it better with Conquest than they can with say agot.
 
That being said, if they do create new warlords, I would like to see some heavy lore come with them. I like to be immersed in a game so lore and theme is pretty important to me. If I played a game solely on mechanics, I might as well play solitaire.

*sigh* Some people really can't help themselves.

They will probably do Asurmen, but I like Fuegan. 
 
However, I must note that ComissarFeesh's argument is irrefutable

Of the information available to us regarding future characters in Conquest, a Phoenix Lord is one of the few things that we can say are going to be in the game with any degree of certainty:
 
 
Since there are only 6 of them to begin with, it shouldn't be too hard to predict which one is going to be a warlord, right? Let me know what direction you think FFG is going to take with this one, or just share your personal preference.
 

 
 

 
 

 
 

 
 

 
 

 

Lucky for us that got it at Gencon. At this rate, all the guys at my local store who want it figure the ship sank with their copies, lol.

Hopefully, it's not Captain Phillips. Or for that matter, Jack Sparrow.

Whilst waiting patiently for Conquest to be delivered, I've been doing intro games for pretty much everyone I can over OCTGN. After this evening, I don't think it's possible for a game to be any closer.
 
It came down to the final planet, both Warlords accompanied by sizeable armies - both of which were ground down to nothing, leaving only the two Warlords slugging it out on top of a huge pile of bodies. The final round of combat came around and neither of us had enough hit points to take a single blow. I had initiative.
 
I struck.
 
The last card in his hand was a single shield.
 
He struck back.
 
I died.
 
I think he's going to order a copy.

Epic ending...in my most recent game my opponent was playing Orks over Chaos and put Runic Armor and then a Cybork body on an Enraged Ork! He was Brutal and had 14 health!! I did get him to 13 damage in one battle with my Eldar over Dark Eldar deck but he retreated before I could make the killing blow. Then, I used the Battle ability of Carnath to trigger the battle ability of Atrox Prime. 1 Damage incoming to all his units at HQ...and then he discards his final shield. Later, he used Iridial to heal that Ork for 13 damage, LOL!
 
It was still a close game, but what I wouldn't have given for a Fury of Sicarius at that point.

Interesting response. I think Dark Eldar are one of the strongest factions based on my games. I've had quite a few constructed games by now - although all decks are made with only one core set because that's all each of us has.
 
I say Orks. They are heavy-hitters but it can be very difficult for them to win command struggles - which means they have no staying power because you run out of resources and cards fast in this game without winning command.
 
Edit to add: Eldar are one of the stronger factions for support in my opinion right now. That Eldar Survivalist can put you back in the game or help you shore up a strong position because of his resource and card bonus. 

I'd agree that Dark Eldar tends to feel like the weakest faction, with Eldar not much stronger. But I think that for both, that's more because their strengths aren't as immediately obvious. Neither of them are "hard and fast" hitters in battle, so in the early stages of learning the game (when people naturally tend to focus on battle), they seem weaker. But I think their penchant for moving, routing and exhausting gives them a different, less obvious strength. They do a lot of things very well, but blowing stuff up is not in the top three.
Which is all just a fancy way of saying, "Depends what you mean by SUCK." Dark Eldar hits the softest, but they do a lot of other, little things well. So they have options. I think, ultimately, Orks are going to prove to be a bit of an underdog in the environment because, while they hit VERY hard, so far, that appears to be about all they do (although they do have about the only "support killer" effect in the core, so what do I know?)

Definitely Dark Elves, even Dark Eldar are more powerful than them in this game.

This. Particularly when you're all starting the game and no one has a great handle on strategy/tactics, anyway, I doubt the imbalance inherent in the available cardset is going to make a huge difference.
 
Plus, if you can convince them to play the game and they like it, they'll probably want to try constructing their own decks, at which point they may well have a "oh man, if only I could include X card" moment, in which case it is quite possible they might change their mind on how strictly they want to interpret their fluff.
 
And even if some factions end up being stronger mono-faction than others, with just four players you can probably construct a mono-faction deck for each faction and just restrict some matchups (or handicap yourself with the weaker deck, since you'll probably be the person with the best handle on the game).

He's not. He was simply saying your friends could come up with a way to accept it. 

If your friends are really into the fluff of things and cannot come up with a situation where the alliances presented on the alignment wheel would not fit their perception of the fluff, perhaps they are not very imaginative?  The only one that really struck me as potential dodgy was Dark Eldar and Chaos, but more specifically Slaanesh and Dark Eldar.  Even that could be explained away by the very fickle nature of the Chaos gods perhaps toying with the Dark Eldar.
 
I could go on about Orks & Imperial Guard, and the Eldar & Dark Eldar alliances which people have been moaning about, but that would be a bit off-topic.
 
As others have already stated, the game balance will be designed around cross-faction decks being a thing.  House ruling mono decks does sound fun, but be prepared for a very distinct tier system to establish itself.