There's already a couple of interesting apps for controlling Live, and/or other configurable interfaces to control .. whatever.
Might be sooner than you think!
My wife wants one (iPad) for her iTunes library. She's a choreographer and travels a good bit, and gets annoyed having to keep up with her laptop all the time. However, until they come out with one that will hold all 75 gigs of whatever (heh) she's got in there, not much point...