Pop superstar Christina Aguilera has reportedly recorded a duet with rapper Eminem for her next album, tentatively scheduled to arrive in stores next year, and the track will also be released as a single.  The two artists had a well-publicized falling out several years ago, but have since made up.  A source close to Aguilera said:  "Christina knows after her last album bombed that she would have to do something special for fans to be interested in her music again.  Its a killer track and is bound to be a massive worldwide hit if released as a single, which is exactly what Christina is hoping for. She cant wait to release the record and prove all her critics wrong."  The insider also said that the singer is working with William Orbit on the album.