I realize that Descent is on it's 2nd Edition. So my question is about this: Is it worth it to go through the backlog of 1st Edition with the 2nd Edition converter?
The Conversion Kit provides 2E stats and abilities for all the 1E heroes and monsters. It does not convert 1E quests, items, treasures, or other components into 2E rules.
You can buy the Conversion Kit without owning a single box from 1E, as long as you don't mind using proxy figs to represent the monsters and heroes you get in that box. By the same coin, the only thing you'd get from buying up 1E boxes are the figures, if you have no intention of actually playing 1E itself. Considering the prices 1E boxes seem to be going for these days, that's a pretty steep price to pay if you're only interested in the figures.
That said, there are some people who prefer 1E over 2E. If you can find an opportunity to play 1E without any financial investment, it may be worth your while to see where you fall.
Like how varied are the games of Descent? Are there only a few scenarios that get played through quickly? Or is there enough variance that keeps them fresh and interesting?
There are only 17 quests (I think) with the 2E base game, but these are strung together into a campaign where you play at most 9 of them at a time. Players choose which ones to play and which to skip as the campaign progresses. You can also play any of these quests as a standalone one-shot if you just want a quick dungeon crawling fix.
Considering how much of the game's focus is on the competition between heroes and overlord, I think it has plenty of variety to keep going. You can play the same quest with different heroes, different monsters, different class builds, etc, and it will be a whole new experience. There is a story to the game, and I think the story element is much stronger in 2E than it ever was in 1E, but at the end of the day this is still secondary to the tactical strategy game.
You probably won't be "bored" just because you've "heard this one already."
And, on top of that, the game is well built for homebrew content. There's already some good-looking stuff popping up on BGG and I'm sure there will be more to come, both from fans and from FFG.
I know they'll probably come out with more expansions for 2nd Edition. But I don't know when. Is there a site somewhere that talks about their schedule?
They've already announced the first expansion set which is (I believe) due out sometime this winter. Not sure if it's projected to be before or after You-Know-When, but I guess we'll see. Other than that I don't think they have any publicly available schedule.
Finally is the game worth it? I used to love playing RPG's with my friends. But we've been playing a lot of board games recently because time is such an issue that none of us have time to come up with our own stories. So I'm looking for something with a bit of a story hook to it to keep us going.
It's sort of like an RPG, but it's not really an RPG. It's better suited to house rules than 1E was, but there's no official allowance for such shenanigans. The Overlord is not a DM, he can't just change things because he wants to "for the story." The Overlord is legitimately competing against the heroes and trying to defeat them. At every turn, he has a chance to drop them on their asses (especially if they approach the game like an RPG and expect to come out on top of every fight.)
As I said before, there is a story element, a decent story element, but the focus is still on tactical combat and the completion of assigned objectives. If you want an RPG in a box, D2E may or may not be what you want. If this makes you hesitant to buy it, I would encourage you to look for an opportunity to try it out before buying to make sure.
If story is what you want, you probably won't like 1E after all, which makes going for all the old content that much less appealing. Sure there's lots of kit there to make your own homebrew 2E stuff with, but if you're looking for a game because you don't have time to make your own stories, you probably also don't have time to make your own homebrew conversions for Descent. =P