Russia? Give me a break. If it weren't for their natural resources, they'd be ... hmm ... like, say, Brasil two decades ago. There is no diverse economic power behind Russia, almost no modern industry, no innovation. Besides, nobody trusts them (not as long as Putin and his cronies do as they please) and imho trust is a pretty important issue in this discussion.

But, yeah, I guess eventually one day there will be other currencies like the dollar now. The Euro could have been one, but won't for some time, not after the EU failed to ensure that their members stick to the rules.