A Kara DioGuardi Photo Gallery

The unveiling of the Dancing with the Stars cast and a fourth American Idol judge made this quite the banner day for TV news.

We had Kim Kardashian and the new Dancing cast pretty much pegged, but the latter - Grammy-winning singer-songwriter Kara DioGuardi joining American Idol when the musical competition returns this January - came out of left field.

We're certainly looking forward to seeing how this major shake-up plays out. Check out The Hollywood Gossip's bio for a little background on Kara DioGuardi - and click to enlarge some of the photos of this new star we posted below...