I don't understand the value proposition because I believe most of these problems (with the exception of possibly the last) can be solved more easily.

Video instructions - even if overlayed in Google Glass, let alone a nearby phone or tablet - will do this fine. This is the most compelling AR demo I've seen that realizes your first idea: http://www.youtube.com/watch?v=eVV5tUmky6c

While it's super-cool tech, I really feel that a video screen or overlay video does the same job just fine. It's still digital content consumption, at the end of the day.

So then there's digital content creation. Well, you can try sculpting or designing structures with your hands some virtual 3D models all day, but I bet (and please correct me if I'm wrong) that it will never be as efficient as using CAD with a screen and qwerty keyboard.

"Assessing volume and packing a truck or car optimally." Hmm, this sounds like an interesting use-case. Could you give an example of where this might save people tons of time and/or money?