Regarding a supranational reserve currency, or even a national reserve currency, any such animal will likely need a nominal gold tie in order to establish credibility...which is why we remarked to a friend (some time ago) that gold is to be owned at all costs, even if it sells down to $5, in which case an opportunity to reduce its average cost would be present.
Related threat
Audit would hurt economic prospects: Bernanke
http://www.reuters.com/article/newsOne/idUSTRE5AR03X20091128
Bernanke is the poster boy for fatal conceit.