After a lot of thought I canceled a March trip to Tokyo today. The news seems to be worse every day, and I did not want to worry about this the entire time I was there and then for 2 weeks afterwards. Just not worth it to me.
The approaching Olympics adds a real twist here -- on one hand they obviously have every incentive to deal with this promptly and effectively as possible, but it also means they have every incentive to downplay the true situation if indeed it gets worse or is already worse than reported.
Just too many unknown unknowns for my taste.