Ellen Degeneres, Simon Cowell

Ellen DeGeneres is already passing judgment on someone on American IdolSimon Cowell.

"I think he's mean and I think he says things in an insensitive way and I don't think that's the way to get a point across," DeGeneres, who's replacing Paula Abdul, tells The Wall Street Journal. "I've called him on it to his face. I'll do the same thing to him [on Idol]. He knows I'm going to do that. ... I think he's got a really good eye and he's a smart guy when it comes to the talent onstage. But he's mean."

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But outside of Idol disagreements, the two are on good terms. DeGeneres says she knows all the judges and has spoken to Cowell on the phone a few times. "We're all friendly. We're all excited," she says. "We're going to be ourselves and see what that is. Simon and I are as curious to see what happens as everyone else. We both like each other and accept one another."

She won't make her Idol debut until February. When she does, don't expect her to be all rainbows-and-sunshine like Abdul was. Instead, DeGeneres plans to be "brutally honest."

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"I don't know if I'll be as nurturing as she is," DeGeneres says. "She always found a positive thing to say instead of attacking. I'll probably try to be somewhat encouraging. ... But I'll be honest. I don't think it helps anybody to be encouraged and not told the truth."

As such, the 51-year-old talk-show queen is already practicing speaking her mind in preparation for her new gig.

"I'm starting to criticize everyone I see, no matter what," she jokes. "I'm like, you thought that was a good outfit to wear? I just start criticizing people."

Idol's ninth season kicks off Tuesday at 8/7c on Fox.