Carnival Corporation CEO Micky Arison yesterday told Travel Weekly that "some people want a holiday in the malls of America, and others want to be on a cruise." He said Carnival has no plans to compete with Royal Caribbean on a size basis.
According to Travel Weekly UK, Arison also said "with big ships you have less flexibility in terms of the ports you can visit. We study these things because we want ships that can go into lots of ports and places."
You can read more about it at Gene Sloan's USA Today blog