I think the cost problem is in the equiping and, expecially, re-equiping older machines. Also, many carriers already provide a universal power port or 110v US-style 2-pin. That is fine if you have your adapter with you (I always do!) but I can't see them changing those to incorporate USB power.
So we are likely to see a hapzard provision acorss the next 10/15 years. Soon it will be standard fit, in the same way that cars are now providing USB interface with power and often to the ICE as well.
Last edited by PAXboy; 1st November 2015 at 16:26.