Back to the story, as I recall, it was stated a while ago (E3, maybe) that you also be fighting humans in the game, not just aliens. Apparently, the PC (I think its Nomad) did something to piss off the company that developed the nanosuit, so you've got the big bad defense corporation mercs out there to hunt you down with their own nanosuits.
One thing I'm hoping for is a few three-way battles. In Crysis and in Warhead, either fight aliens, fight Koreans, or watch aliens slaughter Koreans. You don't really get a chance to get a good three-way going