Electric assisted turbochargers is nothing new. If the turbocharger needs to produce boost, an electric motor helps the turbocharger to reach its operating speed faster.
Earlier a system using high pressure air to spin up the turbocharger was also tested. It's however not easy to get a system to funcion properly. The air system did for example require large air tanks and a pump (thus it was used on heavy trucks) and the electric assisted system will require an electric motor that can withstand the temperature, not increase inertia significantly but still develope the power required.
The idea with the electric assisted turbocharger was basicly to produce boost earlier and to overcome the inertia of the turbocharger. Anything else will require a way to powerful electric motor.
The technology is developed by the turbocharger manufacturers, mostly Honeywell Turbo Technologies from what I have heard:
http://www.orau.gov/DEER/DEER2003/pr...20DEER2003.pdf
http://www.osti.gov/fcvt/deer2001/shaheds.pdf