If you think about it, we already have a "wireless" power transmission device. the common transformer ( primary and secondary winding) Of course the efficiency of the transmission of power is greatly improved via the "iron Core" I have heard of an instance where someone "stole" power from close high tension lines over a rooftop by placing a large coil as close as possible in their attic. The local power company finally wised up and caught him. Even tho an "air core" coupling is inefficient, it might be as one commentor mentioned, what if the voltage and/or frequency as well as turns ratio could affect the process. I'm sure there have already been experiments like this going on for decades. Anything is possible as long as it is within the limits of physics, problem is we don't really know what those limits are.