Denon has added USB integration to the DN-D4500.
Tthe DN-D4500MK2 offers you two loops with live B-Trim editing, two Hot starts for starting from your predetermined point on a track, Cue stutter, Selectable pitch ranges from 4% to 100%, an adjustable Brake effect, and a Key Adjust feature.
The MK2 features two USB slots for connection to USB storage devices containing digital music files. The first is located on the front of the unit for ease of access and suited for USB sticks and the second is on the rear of the CD drawer unit which is best suited for larger USB drives that can then be mounted in a flight case with the product (not included).
Check out Denon DJ for more details.