Major oil discoveries are happening less and less often.  Technology is helping squeeze more oil out of previously "tapped" areas, but still, there is a finite number of barrels of oil underground in the entire world, and eventually they'll be gone.  Though decades away, it's safe to say that crude oil is a dead-end energy source.  It will be replaced, though by what it is still, sadly, too soon to say.  We could be a lot further along in the search for the next energy source.  Whether it's a true alternative energy like solar, or a replacement like crops turned into gasoline, either way at least we win from the standpoint of not being held hostage by foreign oil.

So, maximum supply is going up slowly, while demand is still strong, especially in the developing countries of China and India.  Demand has over time caught up to where it is now ahead of maximum supply.  Until supply is allowed to catch up, or until demand breaks (say, by a recession in China--unlikely, though their economy has slowed some), you won't see prices drop to those "normal" levels any time soon.

Full disclosure:  though I recently dropped my long position in ExxonMobil, I do now have a position in Maverick Tube, a maker of pipeline for the oil industry.  Why?  Because I think the supply infrastructure needs to be improved, and also with high prices there will be more exploration and new wells also.  Just my opinion, that isn't a recommendation for anyone else.