The Marshall Mathers comeback is looking more complete now that he's reunited Bad Meets Evil (with Royce da 5'9"), dropped The Marshall Mathers LP 2, and, apparently, has been in the studio with his "Purple Pills" buddies, D12. According to word on the Internets, Em has three "new" tracks with the Detroit crew. Does this mean the band's back together, guys? We'll see. Until then — since they're not the first group to go separate ways — read on to see what other rap reunions are in the works.