have to say I am with sniglet on this one. M*V=GDP and due to the credit constriction, V is dropping precipitously - so GDP will follow.
Sure commodity prices are high today. But as global demand drops (in line with GDP), suppliers at the marginal end of the curve are forced to shut down and the clearing price drops dramatically.
You can actually build a supply curve for most commodity markets - and when you do this, you can plainly see how just adding a little bit of high-cost capacity at the right end of the curve in boom times raises the clearing price for the whole market. I did this for a consulting gig in the aluminum market. It's a remarkably accurate approach.
When you start seeing articles about refineries, lumber mills and smelters shutting down or being mothballed - that's the marginal/high cost capacity coming off line. You'll see prices falling quickly after that.
here's an example of exactly what I am talking about from Alcan. You can see what happens to clearing price when demand hits a peak. Same thing with oil, copper, etc etc