Biofuels for the most part are very inefficient to produce with our current technology. The exception to this is biodiesel made from cooking oil. Case in point is McDonalds who uses their spent fryer oil to power their fleet of delivery trucks.
Our situation is kind of a catch22. If you plant millions of acres of switchgrass and then it all dies in a drought or massive storms, what would that do for fuel prices and supply? But then again, what happens if we let the politicians and environmentalists lock out our abundant supply of oil and we continue to import not only crude, but refined gasoline?
The latter refers to national defense. Right now it is not possible to power our war machine's planes and boats with biofuels. But with a ever-growing percentage of our fuels being imported, we are slowly being brought to the mercy of other countries who are investing in oil production, such as China, Mexico, and the members of OPEC (plus Canada!).
We need to open the way for a domestic supply of oil in the short term and invest in the development of more advanced nuclear reactors for electrical generation and biofuel/hydrogen fuel cell for transportation long term. We will become Europe and be at the mercy of the rest of the world for their resources if we sit idle.