I believe that the EPA has control over at least part of the mandate. The EPA will allow (require?) 15 percent ethanol content in 2011. Originally the EPA required ethanol usage as a replacement for MTBE. Congress passed a law with huge biofuel mandates in 2005 and increased in another law in 2007. I doubt that Congress will repeal the mandates although the mandates are absolutely preposterous.
Watch the appropriations for biofuels. Scream now in protest, or scream later from pain as we pay for it.
So in other words, the subsidy may end but the mandate won’t. Therefore, the price of ethanol crap gas will skyrocket.