I'm a biofuel skeptic.
It seems to me most biofuels are Rube Goldberg contraptions-- first you take plants that convert sunlight into glucose or cellulose or whatever, then you harvest them and run them through some process to convert them into fuel.
Why not just cut out the middleman and convert the sunlight directly to energy? Solar panels are a whole lot more efficient at converting sunlight into energy than plants. True, solar panels don't grow themselves (yet?), but you don't have to use tractors and huge factories to convert solar panels into usable energy.
I predict that in, oh, 25 years biofuels will be a niche energy technology, used only in places where there's an abundance of organic material available to process that would otherwise just be thrown away (maybe food processing factories will derive their energy from biofuels made from seeds and stalks and stems).
I wonder how much tax money will be sunk into subsidizing biofuels between now and then...