The movie before the other survivors are introduced (which is where the movie ceases to be awesome). That would be an awesome game. It's too bad they didn't make it.
Anyhow, I am getting red flags when I see enemies introduced with guns. I don't care for boring popup-and-shoot gunfights. Having the ability to hide behind structures is great. Hiding from a deadly stalker enemy makes survival horror, not gunfire. I'd rather have Naughty Dog focus on mowing down a bunch-of 'the infected' or finding a way to breakout and escape to freedom. I'm still trying to figure out how they are applying 'survival horror' to this game.
I'm also curious how Naughty Dog will utilize the partner system. It looks like your girl partner can't wield weapons.
edit: Watching the trailer it looks like they will be using Left For Dead fast zombies. The girl uses a knife in the trailer.