Portal cosplay from this big gallery from PAX.
Relatedly, since I mentioned Narbacular Drop drop yesterday and how disappointed I was with the look of Quantum Conundrum, from a Gabe Newell interview:
GN: Well, the thing there -- and I've talked about this before -- that was really scary to me, was that something had happened with this group, that would've been kind of sad if these people all went their separate ways.
Because a lot of times you can look at something and say, "Oh, it's successful because of this person."
EJ: Carmack.
GN: Yeah. Carmack is so clearly the heart and brain of everything that id does. But with the guys who worked on Narbacular Drop, it was like the magic was in the team, and if the team had split up... That was my read. That there were a bunch of games that wouldn't get made if these guys went their separate directions. So I was like, "That'd be a real shame, so we need to keep them together and see what they can do."