Demo is up on PC and 360. Not sure on PS3 yet.

The fucking multiplayer is siiiiiiiiiiiiiiiiiick! It's basically a horde mode with all the gameplay components of the singleplayer. There's also dynamic objective missions thrown in every so often while you are defending.

the single player is amazing, getting to fight alongside anderson was great, when he left the planet and watched the little kid get blown up i almost cried, the game is going to be EPIC