I really like that Lutz cites how previous legislation puts the responsibility on the automaker and doesn't do anything for the consumer. It's important to give people an incentive to use less gas instead of pressuring the car companies to do more. They've done a lot. Despite this, more fuel efficiency is good because it shows that we can do more with less. GM has shown us that they can produce a lot of power with less, and I'm sure we all appreciate that.
Lutz is also right about bioethanol. If we stop subsidizing so much, we can really change the way we fuel our cars. God only knows why the government didn't do anything about that when they decided that CAFE was a good idea.
I like what Zetsche said about diesel, but it could take a decade and a half for people to start accepting diesels as an alternative. You all remember the glory days of imports and the low-quality of American companies. To this day, GM and Ford suffer from the perception that imports are fundamentally better even though they strive to produce higher quality cars that compete on every level from comfort to performance. If diesel were already a growing part of the market, I could see GM and Ford investing in more diesel engines, but they won't see sales benefits for a while. I think GM should continue to focus its resources on technologies already in development that show real potential, like the Chevrolet Volt, FlexFuel, and expanding the lineup of hybrids. Consumers seem to be reacting very well to this.