Just in the last two weeks I read on another SW site that the location decision for C3 is supposed to be made and announced by the end of the month. That's good.
Two friends and I attended Gen Con in Indy on July 26, and it was better organized and ran than C2. Although we waited in line more than an hour for our tickets (we didn't pre-purchase because we weren't sure we were definitely going) the line moved quickly. And there were several little things like coolers of ice water set up in the hallway that made a difference.
Whoever's gonna operate C3 might want to get in contact with the Gen Con folks and get some tips.