The internetz are a'blazes with American Idol chatter, and until anything's confirmed, it's mostly idle chatter. That said, all signs point to last-standing o.g. judge Randy Jackson stepping away from the table. Word is he's aiming to stay involved, most likely in a mentorship role similar to that handled by Interscope CEO Jimmy Iovine. Judge Jennifer Lopez and the honorable Steven Tyler peaced out in hilarious Steven Tyler fashion in July.
That'd leave three seats, if one wasn't already confirmed to be going to Mariah Carey (now the highest paid judge in reality television with a reported $18 million contract). Also, a fourth seat has been re-added so, yes, that in fact does leave three seats. (Yeah, math!) According to TMZ, deals with Keith Urban for $3-4 million and Nicki Minaj (to the apparent dismay of Carey) are in the works.
It's also been "reported" that Katy Perry turned down $20 million for the post, while speculation persists regarding Miley Cyrus, Pharrell Williams, Nick Jonas, Brad Paisley, Diddy, Kanye West, and Enrique Iglesias.