I remain firmly convinced that Apple is planning for 10 or 15 years down the line, when there is no special "thing", just face screens that are light and compact enough to start piecemeal replacing phones as a product category.
In principle it should be possible to do away with screens altogether and generate an image by shining low power lasers from eyeglass frames into the wearer's eyes. This will require some major technology breakthroughs, but I think that's what will really make AR cross the chasm into the mainstream market.
