In the three-season run of the U.S. version of the popular singing franchise, which was originated in the U.K. by Cowell, Lovato was the only singer to return for a second season as a mentor, as Season 1 mentors Paul Abdul and Nicole Scherzinger and Season 2's Britney Spears only served one-season mentorships on the show.
Although Lovato and Cowell have had their bouts of banter on the show and she failed to send a member of her group to the finals in either season, Cowell insists that the move was mapped out from the very beginning.
"It was two seasons, and we've had great fun, but she has to tour next year. We've had fun working together," said the music magnate, who said he didn't have a replacement lined up yet but had "some thoughts" about whom he might ask to fill Lovato's chair on the panel.
X Factor Season 3's Top 3—Carlito Olivero (Boys), Jeff Gutt (Over 25s), and Alexa & Sierra (Groups)—sang their hearts out on Wednesday night with the hope of winning a recording contract with Cowell's label, Syco/Sony Music, and a cash prize of $1 million.
While he didn't divulge which singer he thinks might be selected as the winner of this season, Cowell said that he was impressed by Jeff on his first song and Alex & Sierra on their last song. Lovato was also impressed by Alex & Sierra, whom she referred to as "true winners."
With only a short while until being relieved of her duties at The X Factor, Lovato revealed her upcoming career plans. Let's just say she's not ending her X Factor run to sleep all day.
"I'm going on tour. I'm pretty much going to do a lot of touring this year. I have a lot of stuff planned," the 21-year-old singer said. "I'm really excited to put on a show that I've never really done before. It's going to be awesome. And I plan on working on new music, maybe releasing a new album."
Watch all the backstage interviews with the mentors and the Top 3 contestants in the video above, and tune in to The X Factor Thursday at 8 p.m. on FOX to find out who wins Season 3.