Their specific design and perhaps some of their technologies might be patentable.

But yeah, lots of prior art on the ideas and even some implementations exist. Another source for what was/is obvious to those of ordinary skill this art would be the Wear-Hard Archives (http://www.haven.org/mailman/listinfo/wear-hard). I miss the days when that list was more active.

Even their specific design is pretty close to some old Mann hardware (http://www.glogger.mobi/userpub2.php?username=mann&i=201..., which I've linked to...well, it's "below" currently).

Never knew about that list; time for an archive trawl, I think. Thanks!

Similar to a degree, but I can't tell from Google's publicly shown designs if they are even going for the eye-tap paradigm. So far the camera and display are spatially separated and one has to look up from a scene to see the display.

Though I suppose they may be thinking that common use-cases will involve rotating one's head down a bit while maintaining one's line of sight, similar to "looking over one's glasses", which would bring their screen between the user's eye and what one is looking at.