Increasing the cost of oil could make other energy sources cheaper in comparison, and if the mechanism were a tax that would fund development of alternatives, that would hasten our transition. But it is the speed with which we can discover and refine those alternatives, more than the price of oil, that will decide our energy future.
The question, in other words, isn't just what a gallon of gas costs. It's what a gallon of anything that can replace gas costs. Maybe that's what we should start asking politicians.
As I've posted here before, there is no future in alternative fuels. I support sustainable fuel for the motoring that we'll have to do in the future- and make no bones about it, we will have to do some motoring. Utility workers, for example, require the convenience of some form of motorized transport. However, we also need to be drastically reducing the amount of driving we do, and in most cases entirely eliminating our reliance on automobiles. We don't need to "discover" or "refine" alternatives- they are running around the streets and subways of our cities every single day, in the form of bicycles, electric trains and trolleybuses, and electric commuter trains. We don't need to put something else in our cars, we need to get rid of them entirely, and this is something that the overwhelming majority of posts on the BP oil disaster miss by a mile.