So here's the other thing: the Cayenne Hybrid S is a nice Germanic, generic SUV, but it doesn't really feel like a Porsche, whereas the diesel Cayenne does. Does it matter? Probably not, for a number of reasons. A Porsche badge and a hybrid badge on the same vehicle is some soccer mom's ideal car, and it could also impress the chaps at the golf club. The real enthusiast would have bought a 911 anyway. Why hasn't Porsche gone the whole hog and made a diesel hybrid? Because the stop/start function is a lot jerkier with a diesel engine, but there could well be one in the future.
And then there's the whole VW/Porsche who's-buying-who debacle. If VW's other cars are more frugal and allow the company to comply with CAFE regulations, a hybrid (or diesel) Cayenne may be rendered moot. There are even rumors of VW canning the Cayenne and the Panamera sedan completely if it becomes the owner of Porsche. If that were the case, what would it do for the luxury segment, revive the Phaeton?