This is an interesting observation. As far as I remember, we had a similar discussion in one of our Grundrisse discussion. Although I partially agree with the idea that during the crisis, demand for commodity money increases, which means that fiat money system may have problems, these may not strongly support some Marxist's position that commodity money is necessary to anchor capitalism or fiat money may not survive. This is a huge topic. I guess, we can discuss this issue further at our face to face meeting.
For now, I would like rise a few points.
1-From a Marxian perspective, the commodity money's value (as a commodity) should come from the socially necessary time embodied in it. However, how can we explain the current price of gold in terms of labor theory of value? I feel that the gold prices are mainly driven by speculative purposes as in the case of the price of any other financial assets. So, for me, it would be better to treat gold as another form of financial asset (though it has a tangible character) due to the fact that there is no relation whatsoever between the price of gold and its underlying fundamental value.
2-Furthermore, during the crisis, the demand for treasury bills and bonds went hand in hand with very high demand for gold . That’s why, although all other interest rates were rising during the crisis, the treasury bills and bond interest rates were at their historical low levels. They are still very low. Under current system, treasury bills or/ bonds can be considered a form of claim in terms of paper money (fiat money). It is not linked to gold or any other commodity money. So, how can this be explained in relation to commodity money? I do not have an exact answer. But, I think, It shows that high gold prices may not always an indication of decrease in appetite for fiat money.
3-Capitalism, to be able to function in a worldwide scale ,needs several different institutional structures. In a Polanyian sense, one of the key institutions is a well established monetary system either based on gold standard or Bretton woods type of mixture, or current fiat money. However, as we know from history, pure gold system restricts the trade and exchanges in a way that total quantity of gold restricts the expansion . That’s why capitalism needs much more flexible worldwide monetary system which is suitable to its main tendency of “nestling everywhere and settling everywhere”. Bretton Wood system partially meets this. However, under strain, it works exactly as a gold standard due to the fact that dollar (main currency) is supported by gold reserves. I can argue that fiat system is the most developed and sophisticated system which is in line with the thrust of capitalism for expansio. However, it is also prone to several other problems. There is no anchor within the system and those countries who have world currency privileges (due to their hegemonic or semi-hegemonic position) have enormous amount of power. And, Fiat money system is much more prone to fluctuations etc.
In this sense, for me, commodity money system, mixed system, fiat money system should be discussed as historical and institutional episodes. So, it is not clear to me, a current developments can support the idea that money can be only in commodity money form. Indeed, I can even argue that given the development of capitalism, commodity money can be only burden to capitalist development. It does not have fluidity to support the functioning of current capitalism though fiat money has all sorts of its own problems..In short, Capitalism cannot return to commodity money.
What other people think….?