Well, ethanol does work, what you said is something of a misnomer.. Ethanol policy based solely on corn, is doomed to failure for all the reasons mentioned above. Sugar ethanol, switch grass, etc, and any combination not solely relying on corn, however is an excellent idea. Anything less shows one to be beholden, financially or psychologically, to oil interests..
Energy policy needs to be diverse and open to multiple sources to fuel our energy needs, not bet the farm on one single source...