I still feel that even without a tax credit that biofuel will be of interest to decrease the demand over time of crude oil. It just makes sense especially if the end product is cheaper.
If congress does not pass any kind of Cap and Trade ( a watered down version is the best they can hope for ) they will just switch from legislation to regulation through punitive EPA measures; much like they did with acid rain. Still, this will make carbon reducing / recycling tech profitable.