Have a look at the peripheral for Scratch: The Ultimate DJ
There's ya a first look at the controller for Scratch: The Ultimate DJ.
It has a "free-spinning, touch-sensitive turntable wheel", five buttons, and a crossfader implemented on a functional peripheral created by actual turntable manufacturers Numark.
It's also rumored to have Mp3 functionality.
Sixty songs are said to be included in the game, and in conjunction with the controller, it will run you about $100.00.
Just for giggles, here's a shot of rival DJ Hero's controller. Not being biased, just informative.