Valve Corporation has promised a return to Aperture Science Labs by the end of this year. Portal 2 is currently under development as a standalone, full-priced game. As of this moment, details are scarce and whatever little information that has cropped up about the game has not come directly from Valve.
According to games listing on GameStop, Portal 2 will be released on PC and the Xbox 360. The listing does not mention a PlayStation 3 version of the game; something which is not surprising considering Gabe Newell’s view on the console . The listing also confirms the game’s release date as October 26, 2010; however, this is likely to change. The game's description on the retail website mentions new puzzle elements, more devious trap chambers and return of psychopathic AI GLaDOS from the first game.
We will keep you posted as and when new information is available about Portal 2.