I've been trying to keep up with facts rather than speculation but who knows what's true on the internet. As far as I can tell re cruise ships and novel coronavirus -
World Dream has been cleared in HK and pax have been allowed to disembark after 4 days onboard quarantine, with no further quarantine requirements.
Diamond Princess continues to have new infections, somewhere between 64-71 in all now depending which source you read. Princess appears to be getting better at making people comfortable while confined to their cabins, eg free phone and internet, better tv choices including exercise videos, nicotine gum for smokers (onboard smoking is banned including on balconies) and making telephone counselling available for people who feel their mental health is suffering while confined in a cabin. One concern is that if novel coronavirus can be spread through air conditioning, enforced quarantine on a ship is like putting people into a disease incubator especially if they have no access to fresh air, eg people with inside cabins or window cabins.
Anthem of the Seas is docked in New Jersey USA, empty apart from crew, while it is cleaned and while reports of a case of a pax with novel coronavirus previously onboard are investigated. Pax who were supposed to be cruising on it to the Caribbean are stranded and complaining of little assistance from RCCL.
Westerdam is still at sea for about a fourth day in a row, apparently trying to find a port that will accept it although as far as I can tell there aren't any confirmed cases onboard of novel coronavirus.
No guarantee the above is correct!