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.
I'm really hoping The Last of Us: Remastered will have a long life on PS4. The game mechanics make for an excellent and challenging multiplayer experience. It has a fun Counter Strike style upgrade system, great maps, and highly rewards team players.
It should be even better than the PS3 Factions multiplayer because everyone will have the DLC/Season Pass maps, everyone has easy mic access, and of course it will run even better.