I will no longer attend the SDCC, but I watched them covering Thursday on E! and it looks insane. The celebrities there just on Day One were unbelievable. It's no longer a "comic" convention by any stretch of the imagination. Angelina Jolie is supposed to be there today, I think. Once you've crossed that threshold of pure SPECTACLE, all bets are off. SDCC is officially off my list of cons to attend.
Just to clarify, I'm not a huge crowds type of person. When I used to go to the SDCC, it was always packed, but it was packed with people who loved comic books. Last time I went, it was packed with celebrity-seekers, grandmas, and just overall people that wouldn't have been there 10 years prior. Not my type of scene any longer, but I'll always have my memories.