1.) I think a loop remix feature like that on the yamaha a4000/a5000 and Rs7000 samplers would be great. it might seem kind of lame to some of you but it would be a great start for creating even more complicated stutter effects, drumfills, and so on. Would certainly save users time if the presets were good and there were enough of those presets. Probably wouldn't be too difficult to implement either, considering it could just be a midi note rearranger.
2.) Also i think better metering is necessary.
3.) better pfl section and crossfader(designed for trance and house music not just hip-hop)