SAN DIEGO - Critics will have to wait. Yesterday the only ones hissing were the snakes.

Yes, those snakes. The ones on a plane.

After months of unstoppable Internet buzz, audiences at this year’s Comic-Con International got their biggest bite yet of Snakes on a Plane thanks to an exclusive presentation, including new footage of the film, attended by star Samuel L. Jackson. That’s in stark contrast to New Line’s decision to not screen the movie in advance for critics.

And it’s just one more example of Comic-Con’s burgeoning clout.

Go ahead, balk. But for proof of what a Hollywood hub this comic-book convention’s become, look no further than the roster of A-listers mingling amid the costumed ranks of Sith Lords and superheroes.

In addition to Jackson, there’s Hilary Swank, touting her forthcoming horror film The Reaping, as well as Nicolas Cage and Eva Mendes, set to appear today as part of a promotional push for their Marvel Comics-based Ghost Rider. Sometimes a celebrity’s not even here for a movie. Rosario Dawson showed up earlier to talk about a comic book she’s penning called Occult Crimes Taskforce. Adam Brody, who plays uber-geek Seth on The O.C., is here chatting up a comic he’s co-writing for Wildstorm Comics. Richard Donner, director of the original 1978 Superman film, is expected to be announced as co-scribe of the Man of Steel’s comic book, while Donnie Darko director Richard Kelly is here to drum up support for Southland Tales, his latest film, for which he wrote three prequel graphic novels.

The nerds didn’t just get revenge; they got cool. And there are enough of them — blogging and podcasting and posting — to significantly help (or hurt) a movie or TV series before it even launches. So just as studios have courted the religious right after the success of The Passion of the Christ, geekdom too now comprises its own powerful constituency. And for them, Comic-Con is mecca.

"These Comic-Con people, they have their ear to the ground. They are tastemakers," Marlon Wayans, who’s penning a comic, told the Hollywood Reporter.

Taste, maybe. But that doesn’t mean the convention’s newfound respectability has robbed it of its undeniably goofy charm.

A stroll through the San Diego Convention Centre uncovers not only fans of all shapes, sizes and wardrobes, but a who’s who of ’70s sci-fi, whether it’s Buck Rogers’ Erin Gray or V’s Marc Singer. The very sight of Lou Ferrigno is enough to bring a tear to your eye, harkening back to a simpler time when all you needed was green paint to be an incredible hulk.

A simpler time when Comic-Con, then in its infancy, amounted to comics, toys and maybe a Klingon or two. Now, tens of thousands trek here — more than 100,000 last year, double from five years ago. And with every new pointy ear or cape and cowl that enters the doors, the convention’s significance grows.

When director Bryan Singer wanted to lift the veil of secrecy surrounding Superman Returns last July, he halted production in Australia to come here to do it with an exclusive preview.

The same was true of director Sam Raimi while Spider-Man 2 was being made.

So it’s no surprise both Singer and Raimi will be back this year to discuss Superman Returns, now in theatres, and Spider-Man 3, which isn’t due until next May.

Other films being previewed here include Flyboys, a First World War adventure from Independence Day producer Dean Devlin; Children of Men starring Clive Owen and Julianne Moore with director Alfonso Cuaron on hand; and 300, the adaptation of Frank Miller’s graphic novel with Miller (who just this week signed to direct a film based on the classic comic The Spirit) participating in a panel discussion.

Two years ago, Lost bowed at Comic-Con. Hoping to repeat that success are a number of new TV series set for the fall, the chief among them being NBC’s Heroes, which tells the story of ordinary people who discover they have super powers. The network is debuting a 72-minute version of the pilot exclusively for Comic-Con crowds.

Additionally, Battlestar Galactica cast members Edward James Olmos, Lucy Lawless and Mary McDonnell will discuss the third season of their small-screen remake which, like Comic-Con itself, has swapped camp cheese for mainstream respectability.