A 3D TV has pretty much one use. I can envision dozens of niche apps for Google Glass without even trying that could make real differences in some areas.
How about Glass for an auto mechanic. Look under the hood of a car and it overlays the wiring diagram, exhaust diagram, part you're looking at with price and local availability, etc. Switch layers on and off with a glance or voice command.
Add a bluetooth ODB2 synced to Glass and you can see real-time engine stats as you are working under the hood. No more having to have a stack of manuals or tweak something and look up at the portable computer to see what change it made. You see the changes as it happens.
Add auto recognition of the make and model, so you don't have to look up which manuals.
Ditto airplane mechanics.
I can also easily imagine augmented reality applications for surgeons, dentists, dermatologists and just about every category of health professional.
How about an app for foreign tourists. Auto translate whatever written material you look at. Read street signs, menus, directions, brochures, etc. Probably an audio version of that as well -- automatically translating what you hear. Maybe subtitles.