President Bush's State of the Union address, which called for a nearly fivefold increase in the nation's alternative-fuel consumption by 2017, did little to silence critics who contend that new fuels like ethanol and biodiesel aren't likely to play a major role supplying the world's energy needs in the years ahead. They see two key problems. First, the profitability of many alternative fuels -- without sizable subsidies -- is still in question. This is especially true now that the cost of raw ingredients used to produce "biofuel," including corn, has rocketed, squeezing profit margins for producers of those fuels. At...