Myvu is running a special on their "shades" video goggles, and I've been interested in augmented reality recently, so David Molnar picked up a pair and just tried them out for the first time. The picture quality is decent, but it doesn't block out the world around you. Instead the idea seems to be almost along the lines of bifocals -- the screen is mounted in such a way that you need to look down to see it. If you look straight ahead, you see normally through tinted lenses (the "shades" part). See the link here: http://www.myvu.com/Myvyu-Shades-C25.aspx
This is a little bit of a problem if your idea is to run a Charlie Stross style sight replacement, where you have a camera mounted on the outside of the glasses, then run the video through processing and show it inside the glasses. That application really does need to immerse your eyes, so these won't work.
On the other hand, they do make possible a different approach: a "quick look" screen for presenting information. This would be a good place to put the kind of information which today someone needs to pull out a phone and look at or otherwise distract themselves.
- A continuously updating map w/"you are here" to this screen. Just look down, figure out where you are.
- Driving directions. Since it is difficult to focus on the shades, only a limited quantity of information would be shown: how far your next turn is, and a big arrow indicating whether to turn left or right.