Anybody have any idea how many 1st generation Prius's are on used car lots?
I suspect what will happen with hybrid cars is that by the time the battery pack finally needs replacing, the battery pack will cost as much or more than what the car is worth at that time.
So if the car will run solely on the gas engine, people will continue to do so until the rest of the car pukes as they won't be able to justify the cost of a replacement battery pack; but in the meantime the gas engine wastes fuel dragging along a useless battery pack and other assorted electric drive components.
As I've probably said before; the electric drive components are ready, what isn't is an affordable energy storage system with a predictable range regardless of weather, and a quick way to recharge the things. Until a quick recharge long lasting battery pack made of affordable unobtanium becomes a reality electric vehicles will serve niche markets and purposes.
In the meantime while the magic battery pack is being found, clean diesel technology is probably our best bet for increasing fossil fuel efficiency. After all, if the persnickety socialist Europeans embrace diesels, than we should be able to also. My guess is the EPA is the biggest hindrance to greater diesel adoption in cars in this country.