Well, I have to say that while I think that this is the right decision, and although I think that she should have made that decision in the first instance, I am dissappointed in Camilla. For two reasons, number one, by doing this she is making it more of a spectacle than need be, BUT MORE IMPORTANTLY:
I am dissappointed because while I thought her going was a bad decision, I found it admirable that she was able to make that decision, knowing the controversy it was likely to cause. I am dissappointed because she does not have the courage to stand by her decision. I think that once she made the decision it was her decision and she should have kept it.
Her doing it this way has made her take a step back in the positive forward movement that she had made for me.
Anyway, again, just my opinion.
It's possible that this wasn't her decision. If the Queen's advisors decided that she shouldn't go, there may not be much she could do about it. And of course she's the one who'll take the blame for attracting so much press attention (as though she actually wanted it!) and then being a coward at the last minute.