Chris Velazco wrote a great TechCrunch piece on wrist-based wearable tech and where it is right now; I recommend you go read it. Then come right back.
We're in the walking fish stage of wearable computers
The landscape he describes reminds me of the early home PC market, awash with weirdo designs that flopped (remember when Atari made computers?) and stalwart manufacturers sometimes introduced sideshow products (the IBM PC Jr, which was admittedly pretty cool). Except we've had wearables for a while -- Casio calculator watches, Palm OS and th