Everything depends on the free convertibility of the RMB. China is starting to trade in RMB with certain partners instead of USD. It needs to open up its markets so foreigners can freely borrow in RMB and exchange RMB.
There is already speculation that China is preparing to get the RMB rise against the USD again. When the RMB rises to about 3:1, then China will no longer be seriously affected by dollar devaluation.
To make the rise of the RMB possible, China's internal consumption needs to replace exports. China is steadily moving down that road. I think the trade (and currency) imbalances will resolve itself by 2011 or 2012.
By then, if the US has not suffered hyperinflation, then China can easily shift from dollar reserves to others. Once it does that, it can start demanding that the US borrow from it and repay only in RMB.