If you're still a little confused about how exactly Portal 2's co-op gameplay will work, IGN's uploaded just under 7 minutes of gameplay for you to check out. it's honestly nothing too exciting, which is probably good - why would you want a bunch of the puzzles spoiled for you? - but they do show a bit of how you'll interact with your partner in the game.
In other Portal 2 news, part of the solution to the most recent of the ARG has folks thinking that Valve may try and sneak the game out a few days early. Once the full image was pieced together and the message decoded, it said:
rele4sed/ 'Kick 1t' ahead of schedule. that was a test. my 9oal/ is 2 emancipate s0meth1ng else early. but they're on to me. the systam 1s _ in lock down. i s7ill have access to thirteen off-site chambers and AM= inst4llin/ a test 1n each one. i am going to need a lot more test 5ubjects/ 2 m0ve forward. wa1t1_n9 and AM expecting immediate compliance.
If you pull out all the "mistakes," you get the equation "4/19/2011_7AM=4/15/2011_9AM" and with April 19th being the game's official release date, some are taking this to be a hint that Valve intends to give players an extra weekend of game time. Obviously with nothing official out there, no major retailers have changed their release dates, so it's possible this will only affect people who preordered on Steam. Or maybe it's just a demo, or something else entirely. I guess we'll have to wait and see if anything real comes out of this.