When fully realized, we'll essentially have smartphones baked into the frames of our glasses.
Accessibility to the internet will be unparalleled and it will be able to overlay images with useful data onto the real world.
The way we see things, the company has three problems to solve before
It could easily be overpriced. If you want to buy a very fancy pair of designer glasses, you could easily spend $300-$500. Google needs to aim right in this price range (and not much higher) to keep potential consumers interested.
How will we address theft? People steal phones. People steal tablets. It's not hard to imagine someone walking up to you, grabbing the Google Glasses right off your face, and sprinting away. Will there be a "Find My Glasses" feature?
People might not want to "wear" their technology. People who already wear glasses will have less of a hurdle to clear here – they're already accustomed to strapping eyewear to their faces every day. But a large portion of the population uses contact lenses or doesn't have corrected vision. There will likely be a social speedbump to get over before people are wearing them in public without being self-conscious.
Until then, we look forward to seeing the completed product ready for sale!