Google Glass is definitely an impressive feat of technology. I’m sure they’ll sell a few, as the novelty factor is high.
However; however: I also think these will be the equivalent of the Bluetooth headset or the phone-pouch-on-your-belt i.e. used by people who value function and novelty above style and sociability. Or those who think Robocop was a good look (maybe an overlapping demographic, come to think of it).
The social impact of these is being hugely under-discussed as well. If someone was talking to me whilst wearing these I really think I’d ask them to take them off. It would seem to me hugely disrespectful for someone to either be furtively recording our conversation or looking at my Facebook profile whilst we talk. At least if someone glances at their Smartphone while your talking it’s obvious. Instead of removing these social faux pas, Google Glass will add an element of Russian Roulette to the interaction. I guess at the moment at least they’re so ugly you’re forewarned and can take evasive action.
Time will tell, but this seems to me another example of Google launching something just because they can, rather than because it enhances society or there’s a demand. I’m sure wearable computing will be the future, but not in this form.