Not convinced about power transmission by EM-fields, although the MIT researcher is really discussing a transformer with seperable coils rather than using radio. Studies once indicated that high frequency noise generated by computer switch mode power supplies could travel along power lines to be reradiated, and was linked statistically with cancer for those living near power lines. Recent CE regulations have done a lot to clean up power supplies:
http://en.wikipedia.org/wiki/Electro...r_transmission
There are many problems which make remote power supply to a helicopter impractical. The main ones are how to direct all of the energy accurately to a point, how to stop everything around being fried (including crew), and how to even approach reasonable efficiency. IMHO it just won't happen.
http://en.wikipedia.org/wiki/Electri...r_transmission
The best immediate hope for improved power/weight and efficiency for <500 SHP is the latest trend (with VW in the lead) for very high turbo boost piston engines. Both avgas, and avtur diesel engines would benefit. You get the benefit of piston combustion's high efficiency and turbines large air flow rates for a given engine size/mass. The engine needs to be designed to handle extreme pressures, but new materials and surface coatings are allowing this. Forget 2-strokes, wankels, and all the other weird variations - all of them spew out oil like there was no EPA tomorrow.
http://en.wikipedia.org/wiki/Turbocharger
Nick, IMHO the next power revolution will come from the development of direct thermal conversion technology. It already looks competetive at this early stage (estimate >40kW/kg), which means that with development it will eventually do away with both fuel cells and thermodynamic engines.
http://www.eurekamagazine.co.uk/arti...l-engines.aspx