Unfortunately, as has already been mentioned, the majority of the Carnival Group recent new builds have followed the 'HAL' (Holland America Line) 'Vista' style of design. The exterior of all of them being very similar with a few changes here and there. The interiors have left a lot to be desired as well - P&O's Arcadia when she first came into service was - boring, so bland, no imagination at all!! The advantage of using the HAL concept is obvious - it is cheaper to build on a recognised design with variations than to totally design a new ship from the very start. From the ship spotters point of view it means that most of the ships look the same!! Regretably I think that we will not see any new designs in the near future.
Regards
Metman