We can scratch Ms. Jackson off the list. Singer Janet Jackson was reported to be in talks as a replacement judge/mentor taking the position of the dearly departed Nicole Scherzinger, but she has now suggested her summer tour has her too busy. Alas! What a mentor she would have been. So, who will it be? It's looking more and more like it might be Britney Spears, but... Simon Cowell has been making a lot of noise lately about Katy Perry, an entertainer he describes as "feisty."