Is Commodity Inflation a Self-Fulfilling Prophecy?

The run-up in commodities (especially oil and grain) has been tremendous, and has brought with it a lot of talk about runaway inflation.  Is the discussion warranted?  I can see several different causes for the run-up in prices, some fundamental and some technical, but it seems like it is a positive feedback loop. 

First off, the start of the rally came with the wildfires in Russia last summer.  That concern about supply, and already tight wheat markets, sent grain up significantly.  Then came a U.S. harvest which was below expectation, combined with the Fed announcement of their QE2 program.  Since then, higher oil prices have made ethanol more competitive, driving further demand for corn, and more Chinese grain buying has added to supply concerns.  Throw in the upheaval in the Middle East and more Chinese and Indian demand for oil, and prices have skyrocketed.  These price increases have fueled buy-side purchases based on technical factors, and pension funds and the like have piled in for inflation protection. 

I guess what I see is supply issues, coupled with increased demand, pushing prices, along with fear of the Fed policy boosting inflation concerns.  The increased prices lead to more fear of inflation, plus, the competition between ethanol and expensive oil leads to more corn being ground.  Finally, the Chinese have stacks of (depreciating) dollars and need for commodities, so they continue to buy more.  My conclusion, I guess, is obvious, but prices will continue to rise until they don't.  I don't know what will end up breaking this feedback loop, but it can't continue indefinitely.