Let me ask a different question about oil futures -  How has the futures market done making long term predictions of price?

Very poorly is the answer.  Even in mid 2004, oil contracts for delivery one year or more were actually less than the price then - which was about $35.

It appears that oil traders just project short term trends into the future.  

Alan Greenspan states that long term futures contracts show that our inflation expectations are low.  He's wrong, it just shows futures traders, and Wall Street in general, can't think much beyond the immeadiate future - let alone understand the long term impact of PO.  

It appears that information about future supply problems gets almost immediately incorporated into the spot price (this is why the futures price has no additional information about the future over the spot price). If this did not happen, it would be possible to profit from the difference as pbrewer outlined above.