The Chinese have been buying in small amounts to keep the price low, or more correctly to allow the Cartel to succeed in their price fixing.

I recall comments by Premier Wen Jiabao as early as Jan.2007 and others suggesting diversification from dollar.

They came out of the closet only when it became obvious as to what they have been doing. Now that they are out expect them to be more vigorous and earnest because time of opportunity is fleeting.