I would like to see MIDI Learn/MIDI Unlearn implemented for all or at least most commonly used controls. Right click on a rotary control and a menu would pop up with choices for MIDI Learn and MIDI Unlearn. Then move the desired control on your control surface and bingo, remote control.
This would work quite nicely with my Behringer BCF2000, BCR2000, and my recently acquired TouchOSC for my iPod Touch. TouchOSC allows you to design your own control layout over several pages. I just tried it out on Alchemy and Z3TA+2 and it worked flawlessly. I realize that these are only soft synths but I believe the folks at PG could do the same.