Actually, Biden's statements on coal are the Obama party line. He got this right, but didn't get the nuance or presentation right when talking in a rush to ecowarrior-grrl in Ohio. Here's the full statement:
http://www.youtube.com/watch?v=Z6FvHs3f48E
Basically, when anyone asks Obama about "new coal plants", his response is "clean coal". He can justify "clean coal" by pointing out that we'll be victimized by the world's dirty coal otherwise and that we're the Saudi Arabia of coal. It is a reasonable argument.
Note that "clean coal" doesn't answer the question of "new coal plants".
What Obama doesn't say in a very direct way is that he's opposed to new coal plants until clean coal improves. Actually, that's not even strictly true. What he wants is to cap coal emissions, so that no matter how many new plants are built, coal emissions are capped to the same level. He wants to use that as part of the carrot-and-stick approach to adoption of clean coal. It turns out that in PRACTICE, this means opposition to new coal plants, as clean coal isn't far enough along to permit a new coal plant to go online without breaking the emissions cap.