Well, it's not 100%, but according to Metal Sucks, here are the rumored bands for the 2015 Rock Star Energy Mayhem Fest:

  • Slayer
  • King Diamond
  • The Devil Wears Prada
  • Whitechapel
  • Thy Art Is Murder

Again, these bands aren't 100% confirmed, but I'm down with Slayer and King Diamond headlining!  Now, I love these bands, but I don't know if Slayer and King Diamond alone can sell out arena and venues like DTE and such.  Which, as you'll read on Metal Suck's website, makes me think that there might be a giant headlining act to be announced.

Either way, when more details emerge, your Uncle Ramone will keep you updated.