Add X Factor final perfs

ADD X: Tonight's two-hour spectacular X Factor finale on Fox at 8 p.m. (ET/PT) will not feature Mariah Carey, as hinted at, but Justin Bieber, one-half of the scheduled duet, will be there. Also on hand: X Factor U.K. winner Leona Lewis, Ne-Yo and Pitbull and—in a real head-scratcher—50 Cent. The presence of Lewis will undoubtedly spawn comparisons to the evening's odds-on favorite, Melanie Amaro, who many say mentor Simon Cowell has groomed in her image. (12/22a)