I'm figuring we'll get the usual "three specializations per career" set-up that FFG has used so far, as there's certainly a wealth of Force traditions to draw from. I suspect we'll also see reprints of all five Force powers that have been published to date, since this is the Force-user's book.
While "six careers" seems to be the standard, I'm wondering if FFG will break the mold a bit, and perhaps not provide as many careers. Pretty sure there will be a Jedi career, and I'll be surprised if they don't follow the Consular/Guardian/Sentinel framework that's been in place since the first KOTOR game. But after that, they could probably go in terms of themes for the other careers, with a "magician/scholar" type who focuses mostly on using the Force, a "warrior" type that's more of a combatant with the Force used to bolster their combat prowess, and maybe even a "dabbler" that's a mix of the two. It's also possible they could include a "dark sider" career and specializations (such as the Nightsister and Inquisitor).
Or, they could take an entirely unexpected route and provide a Jedi career, but also a single generic "Force Adept" career with the various Force traditions simply being universal specializations, with the Force Adept simply choosing one of those universal specs as their starting specialization (including the Emergent and Exile). Of course, you might run into a bit of an issue if the Force Adept is too focused on being from a primitive background (WotC ran into this with their Force Adept class in the OCR/RCR versions), so which skills are the default career skills might be a bit of a balancing act; certainly not impossible though.
I don't think we'll see much in the way of non-Force careers, as the muggles already have two core rulebooks with careers and specializations they can pick from, which are flexible enough to cover a wide variety of character concepts. I do figure there will be new species in F&D, and they'll certainly be options for non-F/S PCs, much as Wookiees and Twi'leks are viable options for AoR characters and Mon Calamari and Sullustans are viable for EotE characters.
In terms of Force Powers, if the trend continues from the current material, then I suspect they'll be sticking with the "Force use is generally subtle" paradigm vs. the kung fu wizards approach that the EU (especially post-RotJ) has taken. Really the only truly blatant "Force = magic" bits we see in the movies are telekinesis (the Move power) and Force/Sith lightning, the later of which is easily excused as generally being a corruption of the Force.
While over-the-top Force-users are fine and fun for videogames, someone like Kyle Katarn or particularly Starkiller doesn't work well in an RPG as they'll quickly hog the spotlight from everyone else, much the way a high-level wizard does in most editions of D&D. That's not to say FFG won't include the option to "crank up the dial" to allow certain groups to have such over-the-top characters, but it may just be a sidebar... if it gets included at all. Of course, easiest way to get Starkiller-type PCs would be to drop the requirements of additional Force Points to activate power upgrades, which the EotE Beta proved would give you ridiculously powerful PC Force-users with just a single Force die.
And Force & Destiny certainly doesn't need to be bound to the upcoming movies, especially if it's set during the Rebellion Era, which all indications suggest is going to be the case, as EotE and AoR are both set in that era, and F&D is meant to work in full tandem with those two books. If the new movies are dealt with at all in the product line, it can be as a supplement, same as if they choice to branch out into the KOTOR/SWTOR, Clone Wars, or Legacy eras.