So MIT has been experimenting with magnetic resonant coupling to transmit power at a distance (see press release). There's no new magic here, this is using electromagnetic radiation to transmit energy, just as is done with radio waves. The main difference between radio antennas and these resonator coils is that those vertical quarter-wave radio antennas and TV style rabbit ear and Yagi antennas most people are familiar with are designed more around electrical coupling. MIT's power antennas are designed more around magnetic coupling.

Nikolai Tesla was experimenting with broadcasting power via radio waves 100 years ago, and also lit up lights. What Tesla could not seem to comprehend (although his peers did) was that transmitting radiation like this is still subject to the the same inverse square law. That means that the power you can intercept from the expanding sphere of energy falls off with the area that the radiation spreads out to. A bulb at twice the distance can only intercept 1/4 of the power. A bulb at three times the distance can only intercept 1/9 of the power.

So what happens if everyone sets up a wireless charging station of this sort in their house? Just like the cell phone charger that is left plugged into the wall with no phone connected, the energy not intercepted from the expanding sphere of electromagnetic radiation is wasted and goes mostly into heating the environment around it. In this case though transmitting energy through magnetic coupling is subject to greater losses and is even less efficient. Let's build another 150 power plants to make up for this and our global warming from unused radiation is held in with a nice blanket of carbon dioxide.

Now, what can be done to reduce the losses? Make the gain of the resonator antenna very directional so nearly all of it is transmitted directly to the thing being charged -- so now you need an aiming mechanism for transmitting directional power just like you would with say a laser or microwaves. This makes transmitting the power almost as low-loss as wires. This technology is starting to get more affordable. My favorite application of sensing and aiming technology was best described on Saturday Night Live in the mid-80s - a mini-Star Wars home device for tracking mosquitoes and zapping them with a high-power laser in the middle of the night, while you sleep secure in your bed. Mosquito detected... tracking... whir whir, Snap! Crackle.

Did you know that new cell phones in design are going to be required to remind you 'Cell phone is charged, please disconnect your charger from the wall'? To automate this for convenience, the WiTricity sending unit probably also needs a means to remotely tell the charger that its services are needed/not needed. Call this an intelligent charger - or at least a chatty one. Bluetooth perhaps?

Tracking/aiming and intelligent charger control. I think that is where the true technical wizardry is worth investing in. Using magnetically coupled resonant loops to transmit power in itself is old tech and just a fluff piece useful for marketing MIT and wowing those who desire to worship technomagicians.