What you're referring to is peak oil theory. Within that framework, the problem isn't supply, but cost of production. The more oil you drill, the farther down you have to go to get it and the more it costs per barrel; the danger is in the price of oil becoming too great for it to be a viable fuel source.

This isn't something that's just going to blow over; at present, there is no serious political push for alternative energy. Hydrogen is not a feasible alternative, since we do not have the necessary nuclear infrastructure to create enough fuel to support a hydrogen economy, in large part thanks to the idiocy of knee-jerk environmentalists who know nothing about nuclear energy. Ethanol doesn't cut down on pollution substantially, and it's driving food prices through the roof to boot.

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