If that's his plan, it's not going to happen anytime soon. If anything, the failure of the Euro would be a giant step in the opposite direction. A global currency, if it could ever exist in light of the events of the past few months in Europe, requires the Euro to be saved.
A global single currency would only happen on the back side of a global economic collapse, wars, famines, etc. But I think that is what they are angling for. In Lenin’s words, “The worse, the better.” (For imposing a socialist system rapidly by force.)