Unlike other, more traditional ideas of what an iWatch could be, this patent describes a wristband that uses a bi-stable spring, similar to a snapbracelet.
So though Up may have appealed to some as an intelligent, iOS-friendly snapbracelet, the only snapping that took place was of the fragile components within.
It seems like this technology will not be available for mass production for a couple years yet, so the first generation iWatch may look more like a souped-up iPod Nano or a slimmed-down screen iPhone on a strap than a snapbracelet.