The crowd skews very young here (several authors and artists who were doing Phoenix for the first time commented on this) and heavily into cosplay. But the flavor itself is mostly the same.
More aisles, more people, more panels, more events, more buildings. How has it changed from last year? It's bigger. Tomorrow is going to be the day of madness at Phoenix Comicon, super crowded and full of non-nerds who are attending because, well, it's Phoenix and there's not a whole lot else to do.