Our friends at Screenrant point out that registration has already begun for the 2009 San Diego Comic Con International.
Passes have always sold out a month or so before the show. And with attendance on the rise every year (this year was insane), you might want to reserve your pass early. I recommend grabbing the $75 full pass, which will also get you into the preview night.
And from what I can remember, this might be the earliest pre-order date ever offered in the convention history. The site also confirms that preview night will take place on Wednesday, July 22nd, dashing the hopes of some convention-goers that the show might be extended one more day.