hybrids are coming down in price, if more companies got involved we would see that price drop even quicker. currently the price saved on fuel over service life has been shown to save thousands over the extra expense of purchase, something no other alternative drive/source systems can even come close to claiming.
biodiesel is a good technology, buit it isn't ever going to be a savior because there is currently only 1 mass production operation in the country and it can only supply enough to feed 2 fuel stations(i forget where they are, but willie nelson is an investor). biobased diesel development woudl also end up being hampered by the same supply side expense as ethanol since current prodution of raw materials in this country is not enough to match demands as a food source and as a fuel source combined.
ethanol does not have any negative effect on engine parts while running, it is when the engine is turned off that the fun begins. since there is still some fuel present inside the engine when it is shut off, that is where your corrosion problems begin. current coating technology and evap systems help some, but most of the atomized fuel is still lef tin the engine to settle on pistons and valve faces to corrode the parts.
a little off topic, one very important thing that seems to be left out of fossil fuel debates is that cars are not the biggest users of fossil fuels. the rubber and plastics industries are. just though about that and though it was odd that no one ever says anything about using fewer zip lock bags or buying longer lasting tires to save teh enviroment.
