Insty already linked this article, but since it is one of my top interests I will dup the link.
Its a brief roundup on AltFuels where Ethanol and Biodiesel are highlighted (and rightly so) as possible near term solutions. The section on Biodiesel is very positive, mainly because it is already a great alternative for diesel engines. The cold weather and availability issues are the only real problems, which are solvable.
I think that Ethanol gets a net positive from this piece. I would have liked to see a bit more on alternatives to corn as a feedstock, but it is a roundup for people just entering the realm.
Have a look at the article; it is a worthwhile use of your limited reading time.