Keep a couple of things in mind.
1) Carnival Corp likes to make a design and use it for a long time. Every ship/ship class being a unique piece of architecture isn't really the "mold" they try to operate by.
2) Princess' Royal and Regal Princess are WAY too big for the announcement. Press release said 99000 tons and 2600 pax. Royal/Regal are 141000 and 3600 pax. That's more than just a minor redesign.
3) At the same time though, you can see that between Royal/Regal and the yet to be named P&O ship, there's a new design they seem to be moving toward.
So could these images of TUI's new ship (recognize the funnel design? It's the same as Thomson... the line where the former Westerdam, Noordam and Nieuw Amsterdam all are now use)... so would it be that shocking that there's a bit of cooperative effort in terms of ship design so long as they don't directly compete? And as a German line this would hardly compete with "Nieuw Statendam/Veendam".
The only piece I hve a hard time with is whether or not as a project of STX this design could get moved to Fincantieri or not... but I know that the SPirit/Vista class was moved around and built in multiple yards, so maybe that's not an issue after all.
The hull color is even already set correctly, and the lack of an aft pool in place of two at midship already alleviates one major battle (right?)
Before anyone gets too excited though that perhaps this design is just being transferred to HAL (they are both due out in 2015 as well by the way besides having near identical tonnage and guest counts) TUI has released newer artwork showing this ship as "Mein Schiff 3" with the recognizeable cursive/calligraphy hull design on the former Celebrity ships that make up Mein Schiff 1 and Mein Schiff 2
Liberty of the Seas