The game is out of the zeitgeist these days, but is a lot of fun and has had significant updates since it was last mentioned on Giant Bomb. I bought a four-pack and never found interested friends, so to you this bounty comes.
It's a Steam game, Windows only. Check out the Steam store page for more details. First come, first serve! Please don't ask to just add to your expansive Steam library; the game is worth a play.
@corruptedevil: I think easy mic access is really important for team based games like Factions in The Last of Us. I've only ever heard shit talking from the opposing team between rounds, and muting is trivial.