What else is there to tell, else from what there's already shown? Treyarch isn't giving much more information than what they gave in the trailers, but that isn't little if we investigate it in-depth. You'll surely inform yourself better watching in-depth analysises of the trailers from IGN or Machinima, for example. I'll surely make an analysis soon and upload it to YouTube, not for now though.
What we can get, generally, is that it will be placed in 2025, and the conflict will be something about a narco-traffic top dog from Nicaragua who one day starts a global conflicting movement, getting the power of the top notch futuristic technologhy in the hands of the USA, on an attempt to simply wipe off everybody. With millions of fans in the world, this makes it harder for the army. The trailers expresses how the army wasn't using man armies anymore, replacing them with robots; although this doesn't completely eliminate men, but just a few are left. Sgt. Woods from Black Ops (retired on BO2) was confirmed on the trailer, and there are rumors about Mason and Weaver involved on the game.
I really doubt that any system or script that was shown previously in COD will change, such as the multiplayer in the Modern Warfare games. Even though everything will be more futuristic. But actually, who knows? Maybe they will make a revolutionary change on the script, let's hope that if they do, that it's positive.