Paula Abdul, a judge on the show since it started in 2002, announced to her fans on Twitter that she's quitting, saying she's doing it "with sadness in my heart."
But, "This all came down to money," reports CBS News Correspondent Priya David, citing a source "on the inside." Abdul, David says, "was being offered a 30 percent pay raise that amounted to an eight-figure deal, but that, apparently, wasn't enough."
The announcement, David notes, comes after a protracted contract battle, and the day after Kara Dioguardi, added as a fourth judge last season, announced she'll be back next season. The show's producer called Dioguardi a "breath of fresh air."
Last month, David points out, producers reportedly tripled the salary of host Ryan Seacrest. Abdul, 47, had been asking for a big payday of her own and, with season nine rehearsals about to start, time was running out.
Despite slipping ratings, the program continues to be one of the most popular on TV, with over 26 million viewers per show last year, and 100 imitators around the world.
In a statement, Fox called Abdul "an important part of the 'American Idol family,' adding that Fox is "saddened that she has decided not to return" and wishes her the best.
David suggested Abdul may just be engaging in negotiating hardball.
And EW.com Senior Writer Michael Slezak told "Early Show" co-anchor Maggie Rodriguez Wednesday nothing can be ruled out. "You never know," he remarked. "It's Paula Abdul. And this certainly makes for a nice summer soap opera while 'Idol' is off the air. So, it (Abdul returning, after all) could happen."
Still, he said, "It probably will be (about the money). She may have overplayed her hand just a bit. You look at her projects outside of 'Idol' -- they haven't exactly been blockbusters. Her Bravo showed averaged less than half-a-million viewers. Her music career is kind of stalled. So she sort of needs to wonder what is she worth outside the 'Idol' universe and sort of think about that."
It would be "kind of a shocker" should she actually be gone for good, Slezak said, since she's "sort of like the whacky aunt who shows up for Thanksgiving dinner and you're sort of holding your breath, wondering, 'What is she gonna say?' But, if she didn't show up for Thanksgiving one year, you'd actually kind of miss her."
Should Abdul have seen the writing on the wall when they brought in Dioguardi last season?
"That's a very crowded judges table," Slezak responded. "I think most 'Idol' viewers felt there was a lot of chatter and not enough time on the performers. So, somebody kind of maybe had to be cut. You just wonder why it wasn't Kara and why it was Paula, given her popularity."
EW.com just did a poll in which 21 percent of respondents said "Idol" would be better off without Abdul, 34 percent said she's an integral, if "loopy" part of the show, and 45 percent said Dioguardi should be the one to go.
So Abdul exiting "doesn't really make any sense," Slezak said. "It's kind of a head-scratcher."
Nonetheless, "I think the show will survive without her," Slezak predicted. "The cast changes every single year (in terms of performers)... and the show goes on. I just think it'll be missing a little bit of that unpredictability that Paula brings, and it's a little sad to see her go."