I find that hydrogen is a very impractical solution in the near or long term for many of the reasons that have been listed, so don't be too quick to blow off strait electic or ethanol.
If it is indeed true that "over 20% of all corn in the US goes to making ethanol, and the national average of ethanol use in fuel is about 3%" it is still irrelivant. Once cellulosic ethanol (http://en.wikipedia.org/wiki/Cellulosic_ethanol
) becomes comercially reasonable it could very well take the US very close to energy independence. The amount of energy per acre of fuel crop (corn wouldn't be grown only for energy, but certain types of grasses might) grown will skyrocket, and it is very feasable that the US could indeed grow enough to sustain it's energy demands. The inferstructure is already there for the most part, and the technology is not that far away. Also, while the net CO2 emmisions from current corn based ethanol may not be any better than normal gas, the net CO2 emissions from the entire process of growing, refining, and distrubuting cellulosic ethanol would be much much better than gas.