Kotaku’s got 4 levels of Portal 2 video to show off some co-op action.
The co-op campaign is a standalone adventure that will be double the length of Portal 1. It’s part of Portal 2, which is coming out in February on PC, Mac, PS3 and Xbox 360. In co-op, two players can link up via the Internet, split-screen or through a local connection. Each controls a test robot, and each robot will be armed with a portal gun that can shoot two portals. As they did in Portal 1, the portal guns fire an entry and an exit portal. You need to use the portals to get out of the locked rooms and deathtraps you keep finding yourselves in. Because there are two players and two guns, co-op players will be able to create a total of four portals, but player 1’s portals will be linked only to each other, player 2’s to just his or her own.
Not sure I smell what you’re cooking with that last sentence about the portal linkage, but I’m certainly going take a look. 2 players and a bunch of new mechanics are fixin’ to have the game’s puzzles giving you the brain pain in 2011.