It's an unofficial lineup. But the guy who leaked it is the same one who leaked it last year, and he was correct then.
"Regardless of how it happened, the 2012 headliners will be Metallica, Red Hot Chili Peppers, The Killers, Beck, Beyonce, and Sonic Youth (which is also rumored to be their last show).Perry’s Tent will again feature Skrillex in a set with Korn, Noisia, Bassnecter, M.I.A., Calvin Harris, Flux Pavilion, Wax, Mord Fustang, and Knife Party.As for the other stages, you can expect to see The Shins, M83, Joan Jett & The Blackhearts, Gotye, St. Vincent, Surfer Blood, Kimbra, Real Estate, Crosses, Sleigh Bells, Bombay Bicycle Club, Antlers, Passion Pit, Odd Future Wolf Gang Will Kill Them All, Wale, At The Drive In, Garbage, Missy Elliot, Gaslight Anthem, Guided By Voices, AWOLNATION."
Not as good as Bonnaroo... But it's still gonna be fun as shit