[Nigel Sedgwick tried to post this comment but had some problems so emailed it to me to post for him. I am happy to oblige and thank him for his input.]

I could not get the video to work, so I have relied on this: http://web.mit.edu/newsoffice/2007/wireless-0607.html

A few excepts are:

Realizing their recent theoretical prediction, they were able to light a 60W light bulb from a power source seven feet (more than two meters) away; there was no physical connection between the source and the appliance.

In the long run, this could reduce our society's dependence on batteries, which are currently heavy and expensive.

I note, firstly, that there are no efficiency figures. Just how much power was 'transmitted' to get the 60W received power?

Secondly, there is nothing new about resonant transformers: they have been widely used in radios in the past, especially in the days of thermionic valves. They are still used, though somewhat less-so, nowadays. The only difference is the separation distance, and then the obvious question of efficiency comes up - and is unanswered. Why is the obvious question not answered?

Thirdly, magnetic fields are vectors: the receiving coil will need its axis aligned with that of the transmitting coil: misalignment will lead to less power being transmitted, and will probably lead to further inefficiency (though that will depend on the separation and the surrounding magnetic environment).

What about the health and safety issues? Especially those arising from chance resonances? Mobile phones with milliWatt transmitted power are one thing; transmitting tens or hundreds of Watts is quite another.

As for the batteryless appliances, I can only draw a parallel with the CT2 telephone: http://en.wikipedia.org/wiki/CT2

In the mid-1980s, Ferranti (and subsequently Rabbit) proposed the setting up of a cordless public telephone service that worked within around 50m of public telepoints (which would be sited at railway stations, shopping malls, etc); the service only provided for outgoing calls. Mobile phone technology (of the sort that is now widely prevalent) was, at that time, rapidly advancing: including that of rechargeable batteries (the brick nature of phones being their principal problem). Where now is Rabbit? And the public telepoint concept?
[Even: where is Ferranti? Though that is a somewhat more complicated story.]

It is worth noting that Ferranti's original concept was for a cordless system within offices and factories, with a micro-cellular structure. This was a much more sensible, though the cellular concept of automatic transfer of calls in progress between base-stations was technologically expensive at the time. CT2 technology is now the basis of the DECT standard for digital cordless telephones that are in widespread use residentially.

Why am I writing about CT2 and public telepoints: it was the push of technology well beyond economic benefit, on practical grounds and those of other competing technologies, that should have been obvious at the time (and was to some).

Nigel Sedgwick