I don't know if this has already been posted but vibrato on a pad using the pressure that you are applying on that pad. You could choose for each pad whether your pressure applies to: pitch, cutoff, resonance, speed of LFO, decay, all of these you could choose if you wanted your pressure to move the value that you choose up or down.
This would be absolutely dope. you can kind of do this with the slider but not really. there are some electric instruments and old electric pianos that have this. very cool sounds can be made, almost like a ribbon controller with the pitch so like constant glissando or portamento.