Every summer for the past 40 years, nerds and those worshipped by them have flocked to San Diego for Comic-Con. The four-day event, which kicks off Thursday, brings vampire fanatics, anime lovers, hard-core gamers, and sci-fi diehards together to let their freak flags fly high. It’s become the time when A-list celebrities and big-name filmmakers meet the fans who’ve made them successful—this year, Steven Spielberg makes his debut with Tintin, Twihards get their first look at The Twilight Saga: Breaking Dawn: Part 1, and former Buffy star Sarah Michelle Gellar returns to her geeky kingdom. But after all of these years, is Comic-Con losing its luster? The New York Times reported that movie studios are reassessing their investment in the festival, with Warner Bros., Disney, and DreamWorks not screening films at this year’s conference. Nevertheless, Universal is hosting its world premiere of Cowboys & Aliens at Comic-Con. “That’s where it all started, and I want to give back,” director Jon Favreau told the Los Angeles Times. Find out what else is in store at Comic-Con 2011.