I read a huge blog post about all the possibilities of an iWatch. In addition to everything mentioned here, there was another really interesting possibility: When your iPhone is in close proximity to the iWatch, you won't have to enter your PIN to unlock the phone. It would reset the next time your iWatch is unlatched. That plus heart rate monitor/accelerometer/pedometer, not having to take your phone out of your pocket to view notifications/see who's calling, and a sexy design, could make for a pretty compelling product. I think the idea of having to take your phone out of your pocket just to see who's calling might seem antiquated in a few years from now.