Some new info courtesy of Destructoid:
The game has ZOMBIE PARROTS THAT DROP GRENADES ON YOUR HEAD
There is also a New Game + mode, 20 odd sniper missions, 20 Quest modes, and everything is graded. You can't get all the good stuff without getting the good grades. The game reportedly takes about 10 hours to beat on the first go through on normal difficulty.
Also, from the sounds of it, the opening sequence where you take photos of zombie attacks in the city was take out. I've always know that photography was taken out of the game, but I was hoping that they'd leave it in that one sequence, because that was probably my favorite part of the original .