The turbocharging experts at Garrett are going hybrid with their Turbopac and Dynacharger concepts. The former uses an electric motor to spool up the turbocharger and eliminate lag. The latter also uses the motor as a generator to regulate the charge-air supply (instead of a throttle) and thereby generate the power it later gives back when driving the turbo. The goal of both systems is to provide supercharger response without the parasitic losses.

*as seen in the June 2000 issue of Car and Driver*

I still want to know what happened to the hydrocharger concept that used the coolant flow system, almost like the supercharger is belt driven.