Simon Cowell
Photo: Fox
Before Season 9's top 24 were even revealed, American Idol had already seen its share of shakeups. Paula's out, Ellen's in and Simon Cowell made an announcement that will change the course of the show forever. In May, he'll be leaving Idol for his new talent show, X-Factor.

As the race to fill his seat charges full speed ahead, the question remains: How do you replace someone with Cowell's experience, expertise and charisma? Cowell can't say for sure, but what he would like to see is someone who knows what he's talking about. "Over the years, judges have been replaced by personalities. That, in the long term, will create problems because you have to be able to spot a star," he says. "My advice has always been to find somebody who actually knows what they're talking about and has actually experienced success in the music business."

Could Howard Stern and Perez Hilton be Idol material?