Ellen DeGeneres and I think that other gal will be there again - can't recall her name...

[The show's judges - Simon Cowell, Randy Jackson and Kara DioGuardi - travel across the country in search of the next American Idol. They winnow down the competitors to a select group of semifinalists who sing their hearts out each week in front of a studio audience and television viewers. This season, joined by rotating guest judges including Victoria Beckham, Mary J. Blige, Joe Jonas, Neil Patrick Harris, Shania Twain and Kristin Chenoweth, the American Idol judges visited Atlanta, Boston, Chicago, Dallas, Denver, Los Angeles and Orlando in their quest to find performers worthy of the "Golden Ticket" to Hollywood.

Emmy Award-winning talk show host Ellen DeGeneres will join American Idol as the new fourth judge sitting alongside Simon, Randy and Kara. As the new judge, Ellen will offer her own unique perspective to the contestants throughout the competition.]
http://www.americanidol.com/about/

I usually watch at the beginning of the season and the end..to see who wins..