If I were visiting from China and didn't know about the US, yeah I might cancel...especially if friends and coworkers were to avoid me when I got back.

The words "nuclear meltdown" trigger powerful reactions in people worse than any real threat. SCMP is reporting panic buying of iodized salt in HK and China, in the mistaken belief that 1) iodine is needed as defense against radiation and 2) iodized salt can provide the protection:

"And when salt sold out, some crazed consumers started grabbing bottles of soy sauce by the armful."

I know radiation is not contagious in the sense that you can't get it from people who have been exposed, but I suspect that this nuclear problem may have a similar effect on travel to NE Asia as SARS did.