I had a chance to play it at E3 this year and the game is seriously bad ass. If you like Halo multiplayer you'll love this. Multiplayer is squad based and done in rounds (counter strike style) but it's still pretty tense. It will take people a little while to get used to the weapons and the gameplay style but it's a lot of fun. The fact that the main weapon has a chainsaw mounted on it brings a ton of fun alone (it's a great melee weapon, nothing like cutting someone in half in the middle of a fire fight).
Something that doesn't seem to get advertised about the game is that two-player co-op is baked in. At any time you can join someone else's game in progress without having to restart (at least that's how it was explained to us). If you're flying solo the AI just controls the other dude.
Yeah, I'm a bit stoked about the game :)