here is the site with almost anything you want to know about the "ultra" voyager... or "Project Paradise" as its called on the RCCL Design site.
From what I have already looked at.. some features the ultra voyager has over the voyager is that it goes from deck 0 - 16. I have attached a comparison to the QM2, currently the largest cruise ship in the world. Other notable features: A Bowling Alley, Hard Rock Cafe many other alt. dining restaurants (in addition to the current Johnny Rockets alt. on voyager) and many other very cool features. Note: already comes in addition to popular voyager class amenities such as ice skating rink, rock wall, promenade etc etc
Length: 1271 ft
PASSENGER CAPACITY: 4,326
There is much more to be seen on the site, go check it out!