With pomp rivaling that of a U.S. Supreme Court appointment, Fox finally assembled the new pieces of the "Idol" panel that will be returned to its original three-member format for season 10.
Actress-singer-dancer Lopez and Aerosmith frontman Tyler will have the job of trying to match the offbeat chemistry of former judges Simon Cowell and Paula Abdul.
"This is 'American Idol,"' host Ryan Seacrest said after the new trio took the stage with him.
Tyler said he wanted to join the show because "it's being a part of something much bigger than yourself. ... I want to bring some rock to this rollercoaster and show if you've got the heart, the talent, the feeling to do this you could be the next American Idol."
"I'm so excited," Lopez said. "I'm looking for the next Michael Jackson."
The likely Lopez-Tyler pairing had been reported so frequently that Fox would have had to produce Betty White and 50 Cent instead to generate any surprise.
Cowell announced last January that he planned to leave to launch a new talent show for Fox in 2011, with newcomers Ellen DeGeneres and Kara DioGuardi exiting this summer. Abdul left in 2009 over a contract dispute.
Jackson will be the only original judge when "American Idol" returns in January.
Lopez and Tyler could help "American Idol" reinvent itself for the new season, when it will try to stem a ratings slide and bring in younger viewers. The show's audience has been gradually aging, and advertisers prefer to pitch to young adults.
But Fox and the show's producers didn't match the new judges to the target audience when it comes to age: Lopez is 41 and Tyler is 62. Jackson is in the middle at age 54.
Lopez's films include "Selena," "The Wedding Planner" and most recently "The Back-Up Plan." She has appeared as a mentor on "American Idol."
She was part of the "Fly Girl" house dancers on the comedy show "In Living Color," in 1990, before becoming a backup dancer for Janet Jackson.
"On the 6," Lopez's first album, came out in 1999 and launched a career in pop, Latin, hip-hop and R&B. "Love?" is the latest CD from the Grammy winner, who has twins with husband Marc Anthony.
Tyler brings a colorful and tempestuous history with him. He's fought with his band mates, been in rehab for prescription drug abuse and took a fall off a stage in 2009 that forced cancellation of Aerosmith's summer tour.
"American Idol" was the nation's favorite program last season, the seventh time it's held that position. But it showed rare vulnerability, beaten in the weekly ratings several times by ABC's "Dancing With the Stars."
A total of 24.2 million viewers watched the ninth season's final duel between Lee DeWyze and Crystal Bowersox, compared to the nearly 29 million viewers who saw Kris Allen claim victory over Adam Lambert last year.