The problem with wearable computing has always been how much it costs.  People don't want to wear the same thing every day and washing machines and dryers are extremely harsh on electronics.  Stepping outside the classics like wrist, ear, and eye is going to require a dramatic advantage.  Cell phone watches are possible but holding your risk up to your ear is uncomfortable.<p>PS: IMO eyewear is the final external location for electronics, but it's going to need to be extreamly light, inexpensive and useful to make it there.  Some sort of adaptive bifocal technology that watches your eyes and auto focuses might be the first winner.