First, the economy is almost always a self-fulfilling prophecy. As long as people believe that oil will hit $200/barrel, speculators will buy now under the assumption oil will hit $200/barrel because somehow have already come to accept the fact the oil will be at that price. As soon as people believe that oil will fall in price, investors will back off. Also, as said before, it's very common for investors to jump at commodities when the dollar is worth nothing.
The CEO of BP said about nine months ago that he believes oil will fall back to around $40/barrel within the next 5 years. I don't think it's a coincidence that the oil forecast of $200/barrel is set out by Goldman Sachs, one of the largest investment firms in the world.