Portal 2 will be hitting retail store shelves this spring. On April 21, 2011, you and a friend can get together for some couch or online co-op action with the two bots from Aperture Science. EA will be publishing the retail version while the Steam edition is due out the same day. In a press release EA states:
Portal 2 is Valve's most innovative title in the company's history and will be launched with a first-class launch campaign this April.
I don't know if "first-class launch campaign" means commercials featuring an exploding GLaDOS-style space cruiser reflected in a fallen Spartan's visor as Kobe Bryant and Jimmy Kimmel fire portal guns at each other, all while the Rolling Stones' "Gimmie Shelter" plays in the background, but I can dream. I just got chills. Portal 2 will be available on Xbox 360, PlayStation 3, PC, and MAC. Of course, this is a Valve game, so the whole thing could be delayed at any time.