The new environment looks wonderful, the new big daddy's are going to be awesome and I hope the story will have a good flow. The combat system will have a fresh feeling to it and combining powers with the girl is going to be epic.
I do hope the guys at irrational games overhaul the multiplayer aspect of the series. The online modes of Bioshock 2 are ok but nothing more. Needless to say, this game will stand its ground between the huge releases in the near future.