It has been evident that USD can not maintain its spot as the world's reserve currency. I think this should not be feared and I guess will be celebrated by everyone who does not earn in USD. The world reserve currency always change every hundred years or so

http://www.zerohedge.com/article/history-worlds-reserve-currency-ancient-greece-today

http://www.zerohedge.com/article/history-worlds-reserve-currency-ancient-greece-today