given the GDP report and outlook by Japan, BoJ has little choice but to take a drastic action.
For those who do not believe drastic actions by large (stable :) economies is doable, please see what SNB did with Franc.
Really, what choice does BOJ have if they have to let their economy recover? Their local, domestic consumption is already down enough that any ensuing inflationary effects of a Yen deval won't hurt them much more than what is happening now.
In any case, I can't understand who would want to go long Yen given the present climate? But then, I have been surprised many, many times before.