Good news: President Bush signed H.R. 4520, A.K.A, American Jobs Creation Act of 2004, on 22OCT2004. See www.biodiesel.org website for the announcement. What this means is effective January 1st 2005, there is a .01 tax reduction for each percentage of Biodeisel blended with Dino Diesel, up to a cap of 20%. If you buy B20, your cost per gallon will be reduced by .20.
I'm going to write my State Legislature here in WA ST., and see if they have any similar legislation pending. If the states provide tax incentives like the FEDS have, the price could drop .40 a gallon, and may be cheaper than regular diesel.