Plus, buzz about Janet Jackson joining Cowell’s ‘X Factor’ panel continues to swirl. By John Mitchell Simon Cowell Photo: FOX Simon Cowell is enjoying the rivalry between TV’s top reality singing competitions and would “be up for” a sing-off featuring the winners of “The X Factor,” “American Idol” and “The Voice.” The “X Factor” mentor/judge took to Twitter Friday morning (February 17) to reveal that he “loves the rivalry between all the music shows” and went on to suggest a mega-showdown between the winners of TV’s three biggest reality singing competitions. “Maybe the winner of @TheXFactorUSA this yr should compete with winner of The Voice & Idol in a super final,” Cowell tweeted . “Just a thought. I’d be up for it.” Maybe the winner of @ TheXFactorUSA this yr should compete with winner of The Voice & Idol in a super final. Just a thought. I’d be up for it — Simon Cowell (@SimonCowell) February 17, 2012 Though “The X Factor” did not perform as well as Cowell and Fox had hoped last fall — the notoriously cocky judge even admitted , “it’s going to take a little longer than I thought” for the show to catch on in America — it has been renewed for a second season. When it returns later this year, however, viewers will see a very different panel, as judges/mentors Paula Abdul and Nicole Scherzinger, along with host Steve Jones, were let go in January. Rumors over who will replace Abdul and Scherzinger have been rampant, with speculation naming everyone from Beyonc
