The event I am wondering about is a possible forced upward revaluation of the yuan. I read the other day that foreign currency traders are beginning to stockpile yuan removed from the country (in violation of Chinese law) in anticipation that the yuan can't be artifically depressed for much longer. This, I believe, is similar to what undid Bretton Woods in the late 1960s. (Although in that case it was the dollar, and the belief was that it was overvalued.)
It would be interesting to think about how a revalued yuan would play out in China and elsewhere. In some ways it's almost the mirror image of the overvalued SE Asian currencies in 1997.
A revalued yuan would be the ideal occurrence. The $ is over-valued against the yuan, and so is the Euro. The US is letting the dollar float down to more reasonable levels against the yuan, but leaving the euro high and dry.