Sensor person here. These a problems are all solvable with enough sensors and compute power. What good is it? I am sure that there are specialist applications that make sense, like for doctors and mechanics that want to see schematics overlaid. I haven't seen a single consumer level use-case that makes sense. Games? Sure. Anything else?
I think the military use-cases will pay for hard AR anyway (think Deus Ex HR-style 'see through walls to find targets' or 'target leading' AR), and we'll start to discover the consumer use-cases after the fact.
Actually AR laserquest/paintball/airsoft games immediately falls out of that - now you need to be able to move silently, because a microphone array processing impulse noise superimposes your location on the blacked-out bunker walls. I'd pay to play.
Suppose that you have face recognition + AR. Then you can have an application that keeps track of notes and tags them to people and objects.
So you make a shopping list, walk into a store that it knows, and there are arrows pointing to everything you have to remember to get. Or you are in a meeting, make a note to ask John a follow-up question, then when you meet John again you have a glowing reminder to ask him.
