Commodities Have Reached a Permanantly High Plateau* (or not)

Following up on yesterday's "The End of Cheap Commodities (or not)" which linked via FT Alphaville to GMO's Jeremy Grantham's dystopic view that we have seen a phase shift. Here's the contra argument.
From Clusterstock:

...A March presentation form Stifel Nicolaus' Barry B. Bannister made the argument that commodities are at the peak of traditional, historical ranges. There hasn't been a paradigm busting shift just yet....

and

...MORE

*The most respected economist in the world at the time, Professor Irving Fisher:

Sept. 4, 1929 statement "There may be a recession in stock prices, but not anything in the nature of a crash."

(the DJIA had peaked the day before at 381, it would bottom at 41 in 1932), or his more famous locution ""Stock prices have reached what looks like a permanently high plateau." on Oct. 21.
Black Thursday came three days later.