I just wanted to add a few things i didn't see addressed. First, everyone needs to realize that ethanol DOES NOT give increased fuel economy compared to gas. it is a smaller molecule with less high energy bonds to break during combustion, resulting in less energy for the same amount of fuel. to get the same amount of power off of ethanol, you typically loose about 5mpg.
now, ethanol could be good for getting us off of our dependence on oil. fortunately for us, corn isn't out of the game quite yet, as there are newer methods that convert all of the corn biomass (stalk, leaves, ect...) to fuel, yielding up to 10 units ethanol per 1 unit petrol put in to the production process (for comparison, current ethanol production here is 1.3 to 1, sugar cane is 6 to 1)

also, i havn't seen hydrogen cars brought into the discussion. i know they aren't ready for production yet, but by the time the gas stations are ready, the cars will be. i'm really looking forward to GM releasing their fuel cell cars