The trailer is out now, just watched it on IGN. It looks... good... for a FPS.
I should clarify, the trailer only shows some of the FPS action, but there's a lot more to the game than that. It has the central XCOM base, which you can roam about freely, where you'll take missions off of a map of America where those missions will be to do things like gather data or rescue people or a bunch of other things. You can leave the missions anytime you want and return to base. Using info and artifacts and other things opens up new tech trees at your base to research new weapons and stuff. The base will also expand over the course of the game but it's not clear if you get to choose how to upgrade it or it just handles that itself. So there are definitely some core elements of the original XCOM in there. Sounds pretty good actually, and looks great.