Trading the Australian dollar was a classic play for those who didn't have direct access to China, and a sure-fire winner on the short side as the Chinese economy slowed.
The decline in the AUD reflected not just China's economic slowdown,but also the fundamental weaknesses in the structure of the Australian economy. It was ironic that those who criticized China for its over-dependence on exports fell into the very same trap.
The inclusion of the Yuan into the International Monetary Fund's Special Drawing Rights (SDR) basket of currencies adds further down pressure on the Aussie. Why trade the AUD when you can trade the yuan directly without the complications of using a third-party currency as a proxy?