As I mentioned almost two months ago here on rennteam, the Porsche turbo will be the first car with VTG - variable geometry turbine - in the world for a petrol engine. these turbochargers are very closely related to the vgt turbo built onto the latest Audi 3.0 turbodiesel. in fact it's a variation of these 50mm turbos. the reason why these kind of turbos have not been used with petrol engines so far is the much higher temperature of the exhaus gasses than on a diesel (approx. 100 - 150 C. more).
expect a fenomenal tourque diagram for the new turbo guys!!
and btw. in two days you'll hear the dsg news on rennteam first...

cheers