I just came across the article on his resignation on FT.com just a few minutes ago. Crazy.

I think you are right. His resignation will have to be interpreted by the currency market. On the one hand, you have considerations like carry trade and event risk stealing the yen spot light. However, this morning we really don't have any major economic releases scheduled that would inherently upset the risk balance (though the RBNZ's decision due late in the US session would definitely count as a market-moving indicator in current market conditions).

Even discounting exogenous risk flows though, I don't think this announcement would immediately lead to a yen drop. While under normal circumstances the uncertainty could generate a backflow from the yen, this doesn't seem like it would disrupt too many of the FX factors. The Abe government hasn't done much to help the yen through economic and foreign policy. What's more, this won't likely have much of an impact on interest rate policy from the BoJ since they are already hampered by growth fears and credit problems. On the other hand, should the Nikkei plunge 3 percent on the news, that could inadvertently guide the yen higher.

Does anyone know who his likely successor will be? I'm hoping it will be someone a little more attuned to the domestic economy (and hopefully one who has a strong background in economics with an opinion on low interest rates and memory of the similarities between the hyper investment period of decades past).