I have to say it was a little weird not seeing this game in the masterlist well anyways first some trailers:
Wheatley Trailer.-
Coop Trailer.-
Robot Trust Trailer.-
Panels Trailer.-
Turrets Trailer.-
Edit: More trailers
Teaser Trailer (old but awesome)
TV Spot
Propulsion Gel Trailer (IMO this looks like it needs a lot of timing)
Info:
Only a few details have been given about the game. The game will feature both a single player campaign and a Coop campaign, both containing their own story and mechanics. The single player campaign will follow Chell(Portal's MC) some undefined time after the events in Portal 2. The Aperture Facility is in decay and collapsing, but GLADOS manages to awake once again and intends to keep on doing science.
The Coop side will feature 2 new characters Atlas(Blue) and P-body(Orange). Both manufactured out of personality cores, this two robots will be part of the Aperture Science Cooperative campaign. Featuring 4 portals to play with this mode will test the most avid Portal players into cooperation with another human being.
The game is set to release April 18-19/2011 on PS3, Xbox 360, PC and Mac.