The possibilities are fascinating: Facial recognition and hand recognition are going to be the things that make these worthwhile. That, and a smaller interface, IMO. Google Contacts??
But seriously, facial recognition pops up names and vital info. and even Facebook statuses and stuff. You can know all about people you already know, and learn stuff about people you don't. Networking made easier.
And the hand recognition is where its really at. Once the glasses can tell where you are trying to touch you should be able to interact with the UI in real time.
Then maybe we get eye movement recognition and we won't even have to do that.
My kids are going to have a hell of fun time; absolutely no privacy
but a damned good time.