Portal 2 'Peer Review' pack is coming to Xbox 360, PlayStation 3 and PC tOctober 4.

Valve has finally set a date for the first downloadable content for Portal 2, entitled 'Peer Review' the content pack will be available to download for free on the Xbox 360, Playstation 3 and PC via Steam, this October 4th.

Peer Review includes new leaderboards, a challenge mode for both single and multiplayer and a new test chamber to solve.