One important point to discuss here is technology improvements and environmental conscience. We certainly know Middle-East oil is going to end up and reserves will not meet for more than a few decades so the current concern about it has taken those Fuel efficiencies to different products I'd say oil will remain with low prices or at least stables
Well I think is going to be the opposite thing, at least while they create an alternate energy source. You see our society mostly depends on fossil fuels for most of the things we develop, the less oil there is the higher the price. One the next decades maybe an international war could start just to see who gets to own the last amounts of oil.