Baytex Party for Mac

From BayTex Productions:

This integrated DJ mixing program features support for MP3 and QuickTime files and is designed for both beginners as well as professional DJs. The two-deck interface is reminiscent of Denon hardware equipment and can be controlled completely through keyboard commands if desired. It can also emulate stereo sound on single-output computers. You can perform many common actions such as changing pitch, marking cues, calculating tempo, and so on.