The problem with ethanol fuels is that they are not compatable with 95% of today's cars. Any FlexFuel vehicle is OK, but not others. For one, the alcohol attracts moisture, which rusts the fuel lines, etc. The problem is compounded with carbureted cars...like my old classics. With fi cars that have sealed fuel systems, you have less problems with rust but get into requiring different injectors sizes, PCM calibrations, and material composition of the tanks, lines and pumps (where the alcohol eats away at the rubber lines, O-rings, etc).
Alcohol or Ethanol have a much lower stoichiotometry, which is one reason cars runing on E85 get less mpg than on gas. This is why the PCM would have to have a different setup than factory gas setups.
I'm all for alternative fuels, but give me something I can run in the cars I have now.