Very interesting!
The transmitter would still need to be plugged in to a normal power source. So, they'll charge you for that.
And they'd likely make more off of you because not all of the resonant power gets consumed by the wireless device.
I can see it now. You get the first one in the neighbourhood and everyone starts to visit every day with their cell phones in their pockets and their laptops under their arms...
I've had customers ask about this type of thing when talking about network design - sometimes as a joke, sometimes seriously and I always laugh and say, Not yet, but I'm sure MIT is working on it."
Little did I know...