I would have thought it'd pair with your phone, with the phone doing all the hard work. The glasses really just being a display and recorder.
It seems cool from a technology point, but I'm not sure I want to trust Google (and thereby the US Government) my life. Or am I doing that already by using Google Search and GMail?
Google Glass will be massively popular with the active crowd (kind of how the GoCam got its big break) - I would personally use it in place of recording videos with my phone! I would not wear it all the time though, that's ridiculous.