<quote> its faith that world+dog wants nothing more than a computer they can wave at </quote>
It would be interesting to learn just how many "world+dog" actually equals...
I can understand people that have 5 metre interactive screens, think Jeff Fahey + Lawnmower Man or Tom Cruise + Minority Report, might require this functionality but "world+dog" don't really have the need or the requirement.
However, I am sure that there must be other usages for example: a warehouse person guiding an industrial robot ( modern fork lift), a steel industry worker moving molten lava about the shop floor ( at a distance)etc .... I presume that the army already have some nefarious ideas as well..