Mariah Carey on American Idol: Jennifer Lopez Gives Advice; Ryan Seacrest Puts Out Welcome Mat

Exclusive! Fox president reveals inside details of negotiations, insists Mariah is not a "replacement"

It's official! Mariah Carey is joining American Idol. And she's already feeling the love from Jennifer Lopez and Ryan Seacrest.

E! News caught up with J. Lo and asked whether she believes Mariah will be a good Idol judge. "I think so, yeah! Why not?" Jennifer answered. "She's a musician for a long time she has a lot of experience. And it's that experience you offer them at the end of the day, the contestants just want to get better and grow through the process."

Fox President Kevin Reilly just chatted with us at the TCA Press Tour, pointing out that Mariah should not be viewed as a replacement for Jennifer. "It was never the goal to replace [Jennifer]. And I think they are very, very different personalities. So once Jennifer declared that in fact she felt comfortable moving on, we never actually said, ‘Who's going to be the Jennifer replacement?' And in fact, we were talking to Jennifer and there was a scenario that maybe she would have stayed, but we've decided that this is actually going to be for the best. And we have no shortage of names."

"Replacement" or not, Jennifer tells us she does have some advice for Mariah and any new judges coming: "Just enjoy the journey," Jennifer told E! News at her concert with Enrique Iglesias in Newark, N.J., on Saturday. "There is pressure as far as the live shows, but you know what? Just remember you're there at the end of the day to help those contestants grow and to get to the end and to get to that finale. And whenever I thought about that it always made my job a little less pressure-filled and a littler easier, because it's not about you. It wasn't about me, it was about them. It was about helping them and that always made it a lot of fun for me. I'm going to miss it a lot."

Meanwhile, Ryan Seacrest is ready to add yet another job to his ever-growing resume: Baby-sitter! "Welcome to the fam @MariahCarey!!" Ryan tweeted today after the Mariah news broke. "When u and @nickcannon need a date night, I'm happy to strap on the double baby bjorn :)"

—Additional reporting by Alicia Quarles