The heading is the only real problem, IMHO; there's a lot of AR stuff that (I think) should work fine with GPS-level accuracy. But I'm not sure we have enough horsepower in the RX-51 to be able to cope with head-turning in a non-laggy fashion -- that doesn't mean it can't be fun and even useful, though.

Also, there are other uses of AR not involving absolute positions of external objects -- a simple virtual crosshair overlay for an instrumented gun relies entirely on relative head/gun position, and is probably within the range of the RX-51's processing capabilities, too. (The gun could be a firearm, paintball marker, or even a duck-hunt controller whose only purpose is as input device, although the latter's not really AR.) Then too, with an appropriate camera, you can overlay other imagery (say, edge-detected near IR) on the actual FOV, without caring what objects are seen.

I'm more for cheap than non-dorky, too, but I see your point. I think there's still technical advances to be made, though, to get the price down where it ought to be. Once it can be manufactured cheap enough to sell to non-dorks, I'm sure some designer will make a non-dorky (but functionally crippled) version.