I simply don't see us moving away from fossil fuels any time soon--and I don't see it happening at all without there being some inducement to cut demand (i.e. a tax). We DO need to move away from fossil fuels--as a national security imperative. We cannot continue to be held hostage by a cartel of petrocrats, many of whom are using the profits from our use of oil to fund terror support efforts.
So there, I've said it. We need to raise taxes on fossil fuels. No "cap and trade" bullshit. A plain old tax hike. Offset it somewhere else in the tax code--either in income taxes or through payroll taxes (as Charles Krauthammer has offered). The "free market" isn't going to solve this one, much as I wish it would.
UPDATE: Some additional info on how that free market's working for us, Mudge.