I have been keeping an eye on Brazil and I can't imagine they are going to switch to an ethanol economy if it doesn't have an economic foundation vis-a-vis oil. But what do I know?
The reason Brazil is so successful with Ethanol is first the material used; sugar cane. Sugar cane obviously has more sugar pound for pound then corn and is much easier to refine into alcohol then corn. Secondly, Brazil's emmission requirements are much more lenient then our standards, making ethanol run engines much more economical.