Well, it was awfully commercial. I'd envisioned a lot more of the social stuff -- guild stuff, "friends" who'd never met f2f getting together. But that was pretty thin on the ground -- it was so damned dark, you could hardly spot your friends even if they were there.
Then there's Alice Taylor, whom you may know from the excellent game blog Wonderland (StarCraft origami wars ftw!). Asked about her experiences at BlizzCon, she told Joystiq:
It was okay. It was expensive, and sparse on content, really. Lots of showy stuff from Blizzard, and some from sponsors, and very little from the players, considering, and they're a very important part of the whole thing!
In both interviews, comments are made about the lighting in the convention center. I can vouch for the interior being extremely dark (I'm sure they had a couple of lights on, but at least half of my photos only show dark shadows of people), especially when coming in from bright, sunny southern California!