Therer are some fascinating designs that, instead of maximizing fuel efficiency, are trying to maximize power at the standard MPGs. From what I understand, drivers of the test vehicles are pleasantly surprised.
The thing that will cause me to get a hyrbrid (once the price comes down a bit!) is that I loathe inefficiency. It's always bothered me that engines are running at stoplights. It's insane to throw away all that momentum everytime you hit the brakes. Pollution out the tailpipe means that you haven't burned everything properly where it could be doing you some good.
A vehicle where the engine runs at an optimally efficient speed for the design will last longer, need less maintenance, and run better for its entire life. Also, the engine could be simply swapped out for another one every 200-300,000 miles cheaply if a manufacturer has settled on only a few basic engine sizes/designs.
A cleaner, quieter, gas-sipping car is the result of increases in efficiency. We don't need the government to impose standards... in this case the smarter choice will eventually win out.
The next logical step is to embed induction coils or maybe high current charging dots in special high volume freeway lanes. That would reduce the amount of hydrocarbon consumption at freeway speeds and reduce the size of the battery needed. On braking the power could be sold back to the road for other users rather than having to store it in a battery. Combine that with computer controlled virtual train formation and we can double the capacity of a lane and reduce wind drag.