It's dying before our eyes. I think this is a secular trend: As the Fed manages the markets for policy ends, these instruments cease to be vehicles for price discovery. Increasing leverage in this environment of evaporating volatility seems like fighting the inevitable. But what do I know?
I'm mainly following / trading gold / oil / bonds for the reasons you have indicated. @CL, @GC, @US. Keep in mind, though, that the stock market will eventually give us a good move so we need to stay alert.