This looks far more enticing than Fallout 3,. I still think they need to make a game with slow zombies though...zombie panic source was a lot of fun because the Zombie's had speed limitations, it kind of evened the playing field. And, the reality is in a real post-Apocalyptic world ammo is not going to be easy to find. I want a game like Romero's Dawn of the Dead, one where you have to use your environment and improvise to survive.
But, left 4 dead still looks like a lot of fun. Might as well post this intro video they just released: