I was watching "Two Guys Garage" and they featured a new turbo set-up that locates the turbine/compressor in the BACK of the car. They say that with the increased distance from the engine to the turbo, everthing runs cooler; turbine is cooler thus transfers less heat to the intake air, and you don't cook the oil either. They also claim there is no additional turbo-lag since it is a positive displacement(?) system since the whole thing is pressurized.
There is more info on these sites. Check them out!
http://www.twoguysgarage.com/thisweek/
http://www.ststurbo.com/