I travel on at least 3 Carnival Cruises a year (heading out on the Triumph on the 3rd Feb. 2001 again - twice in 6 months), making it my 17th on Carnival in 6 years and believe that tipping should be at the discretion of the individual. If I wish to tip - it should be in cash.
I usually give gratuities at the beginning of the cruise (that way you receive that "extra special" service) and a final payment at the end (depending upon the level of service received). How do I know that CCL will not "skim" a percentage off the top!
I agree with Alesia, in that CCL is going "overboard" on this idea.