@Mal Huh, interesting that our numbers are so different. I got my 11% here: http://css.umich.edu/factsheets/us-renewable-energy-factsheet
But yeah, coal is definitely on a downhill no matter what. Wind power is now cheaper than coal, so it ain't coming back.
*Edit - Oh, I think I found the difference: my source counts cars and trucks under the "petroleum" category, but yours only counts electricity generation.