Many articles have already covered the Glass hardware; simply put, Google has done a good job designing the device. Glass is light and unobtrusive. The screen looks great, even in broad daylight, and the camera and processor are excellent for such a small form factor. Battery life, though, is the bottleneck: with heavy usage, I can discharge the entire battery in half an hour. I expect this to improve over time; it has to, for Glass to be viable.
Thirty-minutes of battery life? That’s just nuts for any kind of consumer electronic, and it seems like lunacy for something that is supposed to be worn and integrated into daily experience.