As far as hooking the soundplane up "in the box", are you thinking it will have an open protocol like the monome? Or are you planning something more like what the Lemur had, with your own "build a function" mode (never used a lemur, so I don't know exactly how that works)? Something else entirely?
I know Aalto's been your priority the past few months, but man am I excited to see what you're doing hardware-wise.
Open protocol and open source config software. I think open source is the best way to guarantee that the controller will be supported for a long time.
I'm thinking along the lines of a fairly simple app that lets you define areas on the Soundplane and set what OSC or MIDI messages they send.
I like that approach. Very open-ended and non-limiting. You've got my brain going....