Reversing trend, TV takes over Comic-Con

"Star Wars" looms large over Comic-Con this year like a Star Destroyer, as fans await the next edition of the epic film franchise from Lucasfilm and Disney.

Comic-Con is also dotted with fans wearing Superman and Batman T-shirts, anticipating the faceoff between two DC Comics heavyweights in a Warner Brothers movie. And that's about it for movies this year.

Read MoreIs Comic-Con female friendly?

Instead, the halls of the San Diego Convention Center and surrounding environs have been taken over by zombies, heroes and dragons. It's the year TV conquered Comic-Con.

"It's absolutely just the timing of films and the timing of television," said Lisa Gregorian, president and chief marketing officer for Warner Bros. Television Group.

"For television, we've announced all the new shows and the pickups in May, and by the time July hits, pretty much most of the writers rooms are back, we have a sense of where we're going with the new season, and the timing is perfect for us."

"We're seeing a lot more amazing television from networks," said David Glanzer, the director of marketing for Comic-Con International. "I think for a long time films kind of dominated, then I think a lot of cable television, and now we're starting to see a lot of network television producing some amazing stuff."

A man portraying a zombie practices his walk during Comic-Con International 2015 in San Diego.
Harriet Taylor | CNBC
A man portraying a zombie practices his walk during Comic-Con International 2015 in San Diego.

Those broadcast shows include "Gotham," "The Flash" and "Agent Carter," as well as new shows like "Heroes Reborn," "Minority Report" and "Supergirl," a heavily anticipated project which would be the next Buffy the Vampire Slayer. "I think she's better than Buffy," said Gregorian. "She's Supergirl."

Warner Brothers is also benefiting this year from the fact that Marvel has skipped Comic-Con, giving its DC Comics the run of the convention floor. Also skipping the show are Paramount and Sony.

Read MoreNo drones allowed: Comic-Con unveils rules for 2015

Should Comic-Con be worried? "If a studio doesn't come because they don't have something really dynamic to show, they'd rather sit out a year, and come back with big guns ... we appreciate that," said Glanzer.

At the same time, however, some studios may want to focus on creating their own events. While Disney is here promoting "Star Wars," the entertainment giant may hold back some of its biggest guns until it hosts D23 next month in Anaheim.

If this trend catches on, it might impact Comic-Con attendance. "I think if we lose attendance, it's our fault," said Glanzer. "So far we've been very, very lucky."

In fact, Comic-Con is so confident in its fan base that it's launching a subscription on-demand channel next year in partnership with Lionsgate.

"It has to deliver with our fan base," said Glanzer. Programming will include behind the scenes footage along with films and original content. "I like to say it's like a river," he said. "The river's always there, but the content always changes."

—CNBC's Harriet Taylor contributed to this report.