I think it will be the course of history. There is a trend unifying small entities. We have already the World Health Organization (WHO), United Nations Educational, Scientific and Cultural Organization (UNESCO), World Trade Organization (WTO) ... Why money should be an exception?

"The desirable goal of reforming the international monetary system, therefore, is to create an international reserve currency that is disconnected from individual nations and is able to remain stable in the long run, thus removing the inherent deficiencies caused by using credit-based national currencies." (Dr.Zhou Xiaochu)