When the appropriate time comes that technology will not only appear but be ready to easily replace oil. By proper time I mean when there is another oil crisis ( I mean a real oil crisis, not gas that's 2 bucks a gallon ) which is either man made ( Middle East decides to stop selling crude to us ) or natural ( The planet starts to run low on oil ) ( Both scenarios are why I am against drilling in the ANWR at this time. ANWR oil is of far more use to us as a strategic hedge against the 2 scenarios I have outlined). At such a time we will tap the vast reserves in Alaska and Northern Canada while we bring fuel cell, hydrogen and related technologies online.
Until such time, however, oil industry will do everything it can to suppress any technology that could take its place in the near term.