Finally coming to long island! So stoked.
A7X and Korn were confirmed by Munky: http://www.youtube.com/watch?v=0xx-Lb9B8YY#action=share
Other rumors floating around are Suicide Silence, Norma Jean, Killswitch Engage, Cradle of Filth, Deftones, Hatebreed, Meshuggah, The Black Dahlia Murder, and Ghost. Don't quote me on this, but I read that Trivium was confirmed for Mayhem this year, I forget which website though.
If this lineup is true, this'll be a hell of a year.