Of course, I picked it up (both 360 and PC/Mac versions) at midnight, was somehow able to sleep, go to work, and played it that day. According to my recordings, I finished single player in about 5h 30m. I played the cooperative mode with fellow Portal genius Ho7sauce (GT insideout1986) and finished that in 4h 20m over XBL. Hopefully a small disclaimer regarding the fact that the Outside Aperture storyline is based on Portal 1 pre-March 2010 update will keep your classic “x, y, and z happen in Portal 2!” comments from piling up in the YouTube comments.
I’ve loaned out my copy of Portal 2. I still have it on my Mac/PC but can’t take any more time with any distractions. VFX beckon.