Comic book devotees are some of the most zealous fans of any form of entertainment, rivaling, if not surpassing, those dedicated sports enthusiasts who live and die for their favorite teams. It's no wonder then that even the "God of Thunder" himself, Chris Hemsworth, has admitted he's apprehensive about stepping into the epicenter of comic book fandom, the San Diego Comic-Con (SDCC), where he will be appearing for the first time to promote Marvel Studios' latest comic book adaptation, Thor.

"It's a bit scary, the power and devotion [the fans] have. A couple of months ago I was feeling secure and went online to see what people were saying. Some people loved we were doing a movie; some people already hated it. I'll never read comments again."

Acclaimed director Kenneth Branagh, who will also be appearing at SDCC to promote 'Thor', said that one of the first questions he was asked by the executives at Marvel Studios was whether or not he had ever been to the convention.

"I think they were warning me. They said to brace myself, that I'd never seen anything like it."

Years ago, SDCC was more of a novelty than anything, often ridiculed by the mainstream media, which focused more on the imaginative fans who attend the convention dressed as their favorite heroes than on the tremendous amount of talent collected under one roof. Now, SDCC is almost a make-or-break venue for promoting upcoming genre movies. The clearest indication of how important it has become is the fact that director James Cameron unveiled the first footage of Avatar at last year's show.

Jon Favreau, director of Iron Man and Iron Man 2, said that navigating the waters at SDCC can be easy as long as one remembers that the fans' "tastes define the marketplace."

"I think the trick [to winning over fans] is to love the material as much as they do. If they know you're a fan, too, you're going to be fine."

Branagh will be signing autographs at the Marvel booth (#2329) from 11:15 a.m. to noon on Saturday, followed by Hemsworth from 12:30 p.m. to 1:30 p.m. Both will also be in attendance at the official Marvel Studios panel for Thor on Saturday, which starts at 6:00 p.m. in Hall H.

Also, check out this new still image from 'Thor' showing Hemsworth as the Thor's human avatar, Donald Blake, as he attempts to lift the enchanted hammer Mjolnir.