In reply to gdjoselin: Carnival is doing all they can. I do not see how any one can complain.
Any trip you take - do you have guarantees that you will return safely, won't be in an accident, a hotel fire, earthquake, etc. ? Extra costs and inconveniences - that's part of life. If you plan a vacation and then become sick - can you blame anyone for that. The only one this event is costing is Carnival.
We were on NCL when they lost all power - luckily we were in port. Within an hour all bathrooms were filled up, inoperable and overflowing. We had to take a 25 mile bus trip to find a bathroom to use at a shopping center.
I think the cruise lines are fortunate with the number of ships out, that more "bad things" don't happen. You take your chances when you cruise, or get in a car, airplane - or take a walk. Happy Cruising. We are heading for our 25th cruise on Carnival.