My family is in the exact same boat, we were originally schedule for Japan, but had to move our deposit to China, and then this broke out. We are going to wait until the last minute the cancel, in a way hoping that the Wold Health Organization today issues a travel ban for the region and Disney cancels trip through June or July, but my family has decided that it is not worth the risk of getting sick and being stuck somewhere we cannot get any medical help. We would rather lose the $5K we are in (travel insurance included) than lost $40+K after flights and visa's are purchased. We are probably going to file a claim under our insurance to see if they will cover the deposit money we will lose, as someone in our party has a heart condition and will get a doctor's note saying they are not cleared to travel to China with the virus breakout. We will just book a new reservation on another adventure somewhere in Europe would be my guess, it just isn't worth the risk.
On top of it all, we have a close friend who travels frequently to the region and followed the SARS breakout in 2008, the closest thing we can compare it to at this point, she said that it took China far longer than the western world realized to get everything under control and back to normal. This has already effected more people than SARS so while they have tried and contained it, do we really know how well it is contained? People left the region to go all over the world before we really knew what we were dealing with, there are still WAY to many unanswered questions. Hong Kong is a long way from the "base infection" and everything is shut down there, same with most other major areas of China. I feel that the areas effected have far higher infection numbers than are being reported, and the risk is just too great.