A more robust Beatmaker program would be really nice, something that could actually rival the MPC series. Also, the iPad + touchosc would rival a Lemur at half the cost, you can design virtually any OSC/midi (with Osculator) controller with the TouchOSC editor. A Korg Kaoss pad or Kaossilator would be pretty cool to see, the only problem I can see is the lack of ports on the iPad, I can see it as a better midi controller than full fledged music making device, but I'm sure it'll be plenty capable of some digital music creation (the lack of ports would make it difficult to do any actual recording)