Google Glass is a wearable computer, which is worn like a pair of glasses. I'd suggest they just use the words Google Glasses. Of course, being Google, they have to be rather special.
Currently they're an experimental product. Until recently you could apply to buy a pair and they were expensive at $1500, but probably not the most expensive glasses in the world.
Google Glass by necessity features voice commanded applications. Of course using a bluetooth keyboard would be possible, but would disturb the concept, at least at this stage. I can imagine that voice commands won't quite suffice in all situations, and a keyboard is thus not unlikely to be seen as a necessary accessory.
A still-camera and video-camera are included and the recordings can be shared. I would imagine Jay Leno to be interested in being able to record every moment of his life, as he used to claim he already did. Being able to do the recording himself must be a bonus. Further hardware features are a gyroscope, accelerometer, compass and ambient light and proximity sensor.
There used to be some buzz about wearable electronics in the 1980's, well ahead of when it became feasible, which is about now. Back in the 1980's there were no digital cameras, no gigabytes of storage for music or video and PCs were running at "pedestrian speeds", so how did the buzz get started? Things are different now. Ray Ban or Polaroid computers are indeed feasible. How they'll be used will be quite interesting.
Some legislators have already spotted safety problems with Google Glass. Safety is very important, particularly traffic safety. Will these glasses cause distraction behind the wheel? The potential for that is enormous, that's clear. But in the end maybe that problem will be solved by the same company that created the glasses: Google also are experimenting with completely(!) self-driving cars. Those are, in a limited sense, already on the market, because there are cars that panic brake automatically and some that help you stay in the lane or keep a distance to the vehicle in front.
Computers and electronics are getting closer to our bodies, indeed the pacemaker is inside it. It'll be very interesting to follow Google Glass developments. With a computer in the face it's going to feel like it's almost part of our sensory system. Enhanced reality is what it's called now. It's an important step in the evolution of computers.