A future for the SDR?

Concerns have been expressed during the past year about the international role of the dollar. Expressions of concern are diverse and not necessarily mutually consistent. It has been said that an international monetary system that relies so heavily on a national currency is not stable or sustainable - and that even if it is stable and sustainable, it is not desirable. It has been said that with an inevitably depreciating dollar a "tipping point" will be reached at which important agents in the wo