Simon Cowell leaves 'American Idol'

”I’m very sad” were the first words out of Simon Cowell’s mouth when he called in to Ryan Seacrest’s radio show the day after announcing that the 2010 season of American Idol would be his last. But let’s face it, he’s probably not: The British judge is ditching Fox’s wildly popular singing competition after nine seasons to focus on bringing his own wildly popular U.K. singing competition, The X Factor, to America. ”I’ve always wanted to bring this other show over here,” Cowell, 50, told Seacrest. ”At one point I was going to do both. But you know about overexposure, Ryan. You can’t be on TV too much…I genuinely thought people would be sick and tired of me.”

Not sick of Cowell: executives at Fox, who have scheduled the American version of X Factor for a 2011 debut and can barely contain their glee (pun intended) about the prospect of a schedule stocked with Idol in the winter, So You Think You Can Dance in the summer, and X Factor in the fall. ”We now have the opportunity to become the most dominant force in a long time on network television,” says Fox’s head of reality programming, Mike Darnell. ”It’s pretty thrilling.”

Anyone surprised by Cowell’s decision to walk away at the end of his current contract hasn’t been paying very close attention. Although he makes an insane amount of money for Idol (estimated at $45 million per season), Cowell has been musing about leaving since his initial contract renegotiation in 2005. ”We always had an on/off contract so I would never be tied to it,” Cowell told EW in December. ”It’s really a question of how much you can do properly, and run all parts of your business successfully.” He’ll be around this season, of course, helping smooth the judging transition from Paula Abdul to Ellen DeGeneres — whose hiring Fox swears had nothing to do with the imminent flight of Cowell. (Responding to Ellen’s ”If Simon goes, I go” comment to EW last week, Darnell laughs nervously and says, ”We took that as a joke.”) Execs are also dismissing all discussion of future judging shake-ups on Idol as hypothetical, saying only that Cowell’s departure will lead to an ”evolution.” If you ask Idol alums, though, it may be more like a ”gutting.” ”How do you replace his wit?” wonders Melinda Doolittle (season 6). ”You see so many shows try to copy the format, but still can’t get a Simon.” Brooke White (season 7) agrees: ”Simon is a judge, but he’s also a star,” she says. ”And as cheeseball as it sounds, he does have that X factor.”

Fox says it’s leaving the door open for a Cowell return to Idol, but the bigger priority has to be finding a way for Idol and XF to work in tandem rather than sap each other’s strength. Plans for total domination aside, the slide in Idol‘s ratings — down 18 percent from 2006 — means somebody’s gotta do a little patching of the flagship before trying to launch new platoons. And even if X Factor manages to reunite Cowell and Abdul behind a judging table (rumors that have yet to be denied by the parties involved), there’s no reason to expect it will be an instant hit with fans who have already rejected Idol spin-offs like American Juniors. Do we really want to watch more wannabes trying to warble their way to fame and fortune? Fox Entertainment president Kevin Reilly says yes. ”The bottom line is this: The discovery of stars and people going from obscurity to stardom is an intoxicating thing,” he asserts. But even Reilly can’t avoid another inevitability, made all the more apparent by this week’s media frenzy: ”I don’t think The X Factor is going to be just a singing competition. I think it’s going to be Simon Cowell’s show.”

— Additional reporting by Dave Karger, Michael Slezak, and Dan Snierson

What is The X Factor anyway?

It’s a singing competition in which the winner gets a recording contract. Sound familiar? Not so fast: The U.K. version has multiple categories for contestants, including one for those older than 25 and one for groups. Each category gets a judge as a mentor, so much of the drama comes from their squabbling. The judges also decide who goes home from the lowest vote-getters each week until the finals, at which point it’s back to the public to pick the champ.