As of this writing, we're about halfway through PAX 2008. The first day didn't shut its doors until a ridiculous 3:00 A.M., yet people already back by 10:00 A.M. for day two.
I must admit a little bit of disappointment over the lack of costumes here, though. Maybe Comic-Con spoiled me, but the cosplay is light at PAX. That said, apparently Darth Vader and his stormtrooper group took the "Rock Band 2" stage earlier in the day.
If I had seen that, I might not be complaining.