I'll probably never buy one, but a chap at work brought his in and I thought it was actually really cool. The accellerometer-thingamy-jig works better than I thought and the driving game was as responsive as the one on my Wii. Obviously this thread will now be inundated with anti-fanbois droning on about how useless and stupid iPad owners are for getting one, but each to their own, I suppose.
A thumbs up from me 'cos I thought it was fun (so there!).