Prompted by enthusiastic response from its passengers, Princess Cruises is adding a number of signature features from its newest vessels to most of the ships in the fleet. A number of ships have already received updates and in 2010 three ships -- Sun Princess, Island Princess and Diamond Princess -- will follow suit, with extensive drydock periods which will include the addition of signature Princess features such as an adults-only "pocket of tranquility" called The Sanctuary, and the poolside "Movies Under the Stars" screens.