The world is heading towards wearable computing, and honestly, Google has done a fantastic job hyping up Glass. When I first heard about Glass a while back, I told all my friends, thinking it was the coolest thing in the world. The majority of the girls (and about half the boys) who saw the concept told me something along the lines of, "Ewww, why would anyone wear that?" Now here, at the college level, a good majority think it's really awesome. The attitude is changing, and watching the younger generation for innovative product adoption is going to be key in determining success.
Think about initial smartphone adoption. You could've argued that they provided little benefit over a laptop for many features. The displays were small with low resolution, web connectivity was slow, websites weren't optimized for mobile, and the cameras were pieces of rubber duckies. But they were cool, and people found a use for them as technology improved. As techies, we should absolutely not be dismissing first-generation tech.
Yes, voice control is freaking awkward, but there are solutions to that. Thalmic Labs, for example, is coming out with the MYO (go watch the video) which would be perfect for interacting with Google Glass. Make a hand gesture to take a picture, instead of taking out your phone and positioning it? Seems like a natural fit to me.
I'm guessing Google Glass will converge around the $400-$700 price range, possibly with more than one model. Youth adoption will probably drive overall consumer adoption. As with a lot of new stuff like this, it's easy to say you don't need it. It's harder to say you don't want it after you have it.
I bought my first iPhone in 2008 primarily because it gave me access to live bus arrival times and an interactive map. Other reasons that were far less important were the ability to look up random stuff on the internet, the fact that I hated the UI on my dumb phone, and the fact that I was carrying an iPod anyway so one device was more convenient than two. The main drivers addressed a real problem -- finding my way around when I don't have a computer nearby.
I have a feeling you may be right in the long term that Glass may prove successful, but I just don't see anything like the same benefits. My smart phone gave me fundamentally new capabilities. Glass seems to just make them more convenient.