There is no such thing as a commodity bubble.
There is, however, a dollar bubble.
You can't print commodities with the stroke of a keyboard.
You can't feed your family with dollar bills or build a building with dollar bills or power your vehicle with dollar bills.
The dollar is not a store of wealth. If it were, then a house or a car would cost roughly the same in real terms as it did in, say, 1940 (gold, in dollar terms, is roughly the same price as 40 years ago).
With BILLIONS of people in China, India, Brazil and the "Asian Tiger" nations moving from abject poverty to the working class they are going to desire more cars, beef, steel structure buildings, modern appliances and the other products that demand use of more and more commodities.
Meanwhile, Mr. Bernanke is pouring TRILLIONS of new dollar bills onto the heads of people around the world. Each new dollar undermines the value of each old dollar.
Commodities in a bubble?