I was not one of the pre-orderers so I had to take a back seat for about two hours, which was agonizing. I thought my Barnes and Noble did a good job of line control but I wish they had more than four registers going last night. I basically alternated sitting and standing all night with my IPOD blaring (to prevent any "undesirable" shouting out the ending).
As for the events, I got there around 11 and while people were festive, I did not find any activities particularly compelling. They had picture stations, costume contests, scavenger hunts, etc. My Barnes and Noble was definetely teenager heavy although the adults were out in force also.