Ny suggestion is to add a "real" percussion track to run alongside the real drums track. I would love some good percussionists playing appropriate percussion in the same manner as the drummers playing on real tracks. I guess this would be most obvious for latin percussion alongside jazz styles, but I think could also be broadened to other genres - you already have the bodhran for celtic styles, but there would be other applications across pop and folk for example.
It is currently possible to add simple percussion using the loops feature, but giving us a full percussion track would give a lot more flexibility.

Please?!