Christina Aguilera and Enrique Iglesias are scheduled to perform (in honor of 1999, the year Simon first got his flat-top haircut), as well as our reigning Idol, Kris "Not Adam Lambert, The Straight One" Allen. There are plenty of rumored appearances, too, ranging from Janet Jackson to Hall and Oates. (Those greatest hits albums aren't going to sell themselves, now will they?)
But wait! There's more!
"Idol" finales bring back the entire Top 12 of the season, and often the singers get paired up with established acts, so congratulations random dude who hoped to see Paige Miles and Insane Clown Posse perform together.