China has entered into two currency swaps with Hong Kong and South Korea. This move indicates that the Chinese government is acknowledging the grey market activity of yuan trading already present in South Eastern Asian economies. It also signals that China is working its way to pacify US's call for yuan appreciation. Given time, yuan will likely gain enough currency in the region to establish itself as a trading currency alternative to the dollar. By then, some economies will likely switch their currency peg or semi-peg to yuan. One most likely candidate would be Hong Kong. 

Still Restricted, But China’s Yuan May Gain Currency Abroad