The Chinese currency situation can be boiled down to a few bullets:
Concerns about the trajectory of Chinese economic growth
Fears of a large scale devaluation waiting in the wings
Capital is fleeing from the country at an alarming rate
Yuan value is weakening due to all three above
PBOC is spending nearly 800bn a year to slow the weakness
PBOC can't raise rates, doing so would further slow the economy and further complicate an already massively overlevered economy
PBOC can't cut rates, this would exacerbate capital flight out of the country
Seems the logical solution is some effort to limit both the avenues to and volume of Yuan convertibility. Simply put, force more Chinese to hold more Yuan. Believe it or not, the World's bankers, agree!
BOJ Kuroda and IMF Lagarde are essentially on record supporting Chinese capital controls. Draghi would very likely support some strengthening of the Yuan to make his job of weakening the EUR easier and further incent purchases of European goods. Yellen would certainly applaud some stability in the Yuan to reduce USD strength and make the Fed's 4 hike "mission" in 2016 a bit more palatable.