I have a really hard time believing this will actually happen. Here're the things:
So that means they would have to start this new currency using non-Euro countries that also didn't want to move to the dollar. Then, they would have to sell off their dollars. The best part is that IF their new currency takes off, they'll take significant losses on the sale of their dollars (cause who would buy them instead of the new fabulous China-backed currency?), which would actually weaken their new currency. Plus most of the countries who would sign on would be either a)poor or b)run by crazy people (or both).
Sooo, basically, calm down, Michele Bachmann, is what I'm saying.