The ongoing debate between the supercharger camp and the turbo boys isn't likely to die along with large, fuel-thirsty performance engines. In fact, Eaton believes that the market for both power-boosters will continue to grow at an extremely fast pace along with the rising price of gas. Because manufacturers are looking to downsize their engines, power-adders like the supercharger are becoming increasingly necessary in order to deliver the kind of performance new car buyers have come to expect along with the low fuel consumption that is becoming increasingly necessary.
Unlike the high RPM power generally associated with heavily-boost turbocharged engines, superchargers produce added power at all engine speeds. The downside is that engine power is used to drive the compressor, which reduces the available power gains somewhat. In order to make up some of that lost power, Eaton is developing variable-speed superchargers, which will allow for good power from idle through redline with a reduced strain on the engine. For our part, we fully support the use of both turbochargers and superchargers on any and all new cars. Solely in the name of fuel economy, of course.
[Source: Automotive News - sub. req'd]