We haven't cancelled -- yet. I'm really hopeful that my DD and I will be able to go for our 11/29 - 12/3 trip. We've really been looking forward to it. Nevertheless, it is hard to predict what the future holds and if things get crazy, we might need to cancel. My husband, who will not be going with us, has taken a "wait and see" attitude. He's not completely comfortable and I will not compromise his comfort and well-being for our trip. (Gosh, I sure hope we can go!)
My 6 year old DD does not know much about what is happening with respect to the 9/11 attack. Fortunately, her school did not turn on the televisions and subject the children to the repeated viewing of the plane crashing into the WTC tower. We also did not have the TV on at home (nor did her caregiver) while she was awake. We've explained only minimally what is going on -- it's all she can process.
While I'm hopeful that we won't have to change our plans, it may come to that. Sure, she'll be disappointed, but it isn't her first disappointment and won't be her last. I figure I can fake an illness if I need to. That being said, what all of our children crave most is TIME with their parents. So, I will still take some time off of work and spend time with her. It might just be to go the YMCA pool or an afternoon of shopping where we can ride the escalators for an hour for fun or going to the "hands' on" museum -- something. There must be fun things to do close to home for everyone. It's not the greatest substitute for WDW, and we will go back there again, but it can still be a special time.
That's my two cents!