yeah, this is brilliant, i've been reposting it a lot of places.
well, not even so much the iTunes part, just because I dont use mine for much mp3 playback, instead I stream internet radio in the car, but the ability to mount my 6700 as a hard drive is groundbreaking to me as a Mac user.
Anyway, I assumed you were probably on here too, thanks for the tutorial at pdaphonehome or I'd have never known about that...
The other killer app for me is a P2P program called Pocket G2. Its nifty and all to have a piece of gear that can play back music, but to have that same piece of equipment also with the ability to acquire music on demand is real convergence. No need to go back home, sync with iTunes or whatever, just search, download, then play.