Heres what i've gathered from watching a interview..
1. Bettys cost 1000 points
2. Multiple doors to open, save those points up!
3. As zombies are tearing down windows, they reach through and try to attack you, be careful!
4. Mp40 available on the wall
5. Zombie killcam?
6. Perk-A-Cola machines do not work until you activate the generator (starts the door thing)
7. Animations are better, i.e: run more realisticly, walk more like zombies..
8. They can kill you quicker.
9. Fours players are split into pairs, you then have to try and meet eachother to get to the generator room.
10. Look on the video, you'll notice when the electricity is on the random box will start floating in the air!
Thats all for now, i'll post more when i can find more.