Burns Modular recently released their DJPas MP3 DJ app for the BlackBerry PlayBook, which looks as though it was a WebOS or Android ported app. You can mix and scratch 2 MP3 files at the same time. Features a 3-band EQ, multitouch mixer and crossfader, split output for headphone cueing, waveform view and multi-directory library.
The developer says the app is still under development, but that they will continue to work hard to push out updates. DJPad MP3 DJ app is available for $2.99 in BlackBerry App World here. Check out the demo video below: