I think we're all missing the point of the hybrid.
Yeah, the TDI gets better milage than the Prius, but whole point of the hybrid is to help us learn to give up oil consumption.
The hybrids (inluding the flexfuel cars and trucks) are out there as a start to getting away from using the dino resource.
Little by little we will find better technology, better ways to make fuel and better engines to run on the new fuel.
The whole 'go yellow' camp is crap right now because of the amount of energy it takes to make ethanol. It costs more in energy to make than the amount of energy that ethanol can give. So in the future we learn to make it cheaper and faster and we make engines that run more efficient on ethanol than they do gas, diesel or electricity.
The Prius, not an ethanol vehicle I know, is just the start of a new road.
It doesn't beat the TDI but it does run partly on electric power, so it does other things that are better, like less emissions.
I'm not a big fan of the small hybrids. I've got 4 kids to taxi around and no one is making a nice safe hybrid suburban yet.
But at least it's a start, right?