Simon Cowell

To hear Simon Cowell tell it, The X Factor judges are far from being finalized.

Oh, he'll confirm that Fergie's name was "put forward" and, yes, Gloria Estefan showed up at Thursday's Miami open auditions, but other than L.A. Reid, no one's a lock.

Simon Cowell's X Factor will have two judges

Cowell told reporters on a conference call Thursday that he didn't even know Estefan was going to get involved. "Out of the blue, she turns up and apparently she did fantastic, and I had no idea she was going to be there," he said. Could she be angling for a permanent seat? Cowell seems open to the idea. "She's a sweetheart for doing it and apparently it made a big, big difference today. She gave everyone a lot of support and encouragement. Not a lot of people would bother to do that."

 "I've found the whole process to be kind of interesting in terms of who's enthusiastic to be on the show," Cowell continued. Other names that have recently been rumored (or re-surfaced) as possible judges include Jessica Simpson, Nicki Minaj, Paula Abdul and Cheryl Cole (who is a judge on the original UK edition).

Report: British singer Cheryl Cole joining X Factor

But it doesn't sound like the show, which doesn't launch until the fall, is close to making an announcements. "We're still having nightly arguments with everyone trying to get everyone to agree," Cowell said. "If you asked everyone involved with this show who they'd like as the panel, you'd have about 25 different opinions. I'm used to this. I've done shows in the past where the day before filming we still haven't agreed on the fourth judge because people freak out, they have different ideas, another name comes into play..."

Earlier on Thursday, Fox announced that beginning April 8, X Factor was launching stand-alone "audition studios" in several cities across the country including Honolulu, Phoenix, Anchorage, Ala., Kansas City, Kan., and Denver. The booths will allow contestants to record a 90-second a cappella audition on video, which will be evaluated by the same producers who judge the open cattle call rounds. This brings X Factor auditions to 12 cities.

"We could only go into so many cities to do the open auditions. But the booths came to my attention about a year ago and the idea is to go into as many cities as we can," Cowell said. "It's like doing an audition in front of the producers or the judges. Everyone will be effectively auditioned by a producer. The idea of the show is we've invited the whole of America to audition and this is another attempt to get the reach out, really."