American Idol's New Judge: Mariah Carey

J.Lo, who? Mariah Carey has officially signed on to be American Idol's newest judge, reports TMZ. The singer/notorious diva is reportedly snagging a $12 million paycheck, but sources are already muttering, telling TMZ that Carey was a "nightmare to work with" when she appeared as a guest mentor in 2008. The announcement was made today at TV Critics Association Summer Press Tour; Idol still has one judge's spot to fill. (Read more Mariah Carey stories.)