The only weird thing (besides finding out that the Comedy Central crew was more hardcore than we'll ever be) was the presence of a bunch of WB stars, desperately looking for other celebrities to relate to. They were pretty nice, even though they didn't exactly talk to any of the South Park crew members.
Trey gave a shout out to Sean and J.J. (see item below) and then he and Matt left the room to go drink. They usually don't stick around for public viewings of South Park.
Anyways, all went well, except the sound at the Conga Room went a little buggy a couple of times. The funny thing is, we usually don't finish episodes until the last minute, and this event was taking place over a week before airdate. Needless to say, after some very untimely technical difficulties, the episode finally made it's way to the event with seconds to spare. It was open bar and the Yankees were playing, so no one seemed to mind. A little work was done on the show afterwards for broadcast, but you probably wouldn't even notice the difference.