Turning the IMF into a gold miner?

I was speaking with a colleague shortly after I heard the announcement of China's proposal of the eventual replacement of the USD with IMF SDRs, and I think I said "Oh my God, they want to turn the IMF into a gold miner."

I thought there would be some practical impediment to SDR really becoming a true reserve currency in its own right, rather than an accounting basket. Namely, how would the IMF become a central bank without having underlying central banking authority over currencies?

Unfortunately, it's blocked in China so I can't link directly to it, but I just read a Michael Pettis post that delves into a few of the practical issues with the plan. Some were also pointed out by my colleague right away:

1) Liquidity of the USD (both in terms of treasuries and other securities in the capital markets)

2) The US's role as the principal deficit nation with the surplus (thus, reserve accumulating) nations. Or as Pettis put it, the willingness of the US to deliver currency to reserve nations by way of our trade deficit.

3) The decisiveness and ownership mentality of a national central bank.

One of Pettis' more interesting tidbits was on the prospects of the IMF becoming a 'gold miner':

"Perhaps the SDR is a covert way of getting back to something resembling the gold standard by creating a fiat currency with very strict rules about its expansion. If that is the case, the SDR almost certainly won’t last long. Since we’ve gone off the gold standard we have forgotten how brutal and unforgiving gold-standard discipline can be, and I think it was Barry Eichengreem who argued in Golden Fetters that the gold standard could only work in a society in which the poor and the weak have little political power, the voting franchise is limited, and the impact of monetary policies on underlying economic conditions was not widely understood." [Trouble is, I'm not sure some in the Chinese government would find that sort of society distateful. ]