Sneak Peak of Scripting Can Be Seen In Leaked Gameplay
If you watch the footage of the leaked Dead Living Zombies DLC, I think we can see some of the scripting capabilities we will be receiving, such as being able to trigger explosions just by entering an area, having planes crash, and allowing cars/objects to slide down hills and such, all being triggered by apparently just entering an area as oppose to having to shoot something to cause it to happen. This coupled with the rumored pallet of destructible objects, could lead to a lot of interesting stuff, especially in co-op.
https://youtu.be/RVwlL1blYlU?t=1h14m53s start watching at 1:14:53, about 3 scripted events occur back to back.