My personal bet is that Google Glass is the Newton of wearable hardware. It's directionally correct, but way too early for the available hardware and the existing ecosystem, and too expensive as well.
As a happy owner of a Pebble, I definitely get the value of going beyond the phone screen. And as a sci-fi reader, I fully expect that everybody's going to end up spending 99% of their time intimately connected to tech (and the broader world via that tech). But I don't expect head-mounted UIs to be popular outside of tiny niches for 15 years, if ever.
As a happy owner of a Pebble, I definitely get the value of going beyond the phone screen. And as a sci-fi reader, I fully expect that everybody's going to end up spending 99% of their time intimately connected to tech (and the broader world via that tech). But I don't expect head-mounted UIs to be popular outside of tiny niches for 15 years, if ever.