I think they will to some extent. In an interview with the people who made the ACII cinematic (Digic Studios) (see: http://www.zbrushcentral.com/showth...gic-Studios-on-the-Assassin-s-Creed-Cinematic) they said:
'Most of the characters were built from scratch. For example, all the cloth on the hero had to be simulated so we could not use the assets from Ubisoft directly. However, we've used them as 3D references and followed them very closely. But in some cases we could also rely on the high-res models themselves, which helped a lot in making the deadlines.'
That said, I'd expect ship models were indeed shared.
'Most of the characters were built from scratch. For example, all the cloth on the hero had to be simulated so we could not use the assets from Ubisoft directly. However, we've used them as 3D references and followed them very closely. But in some cases we could also rely on the high-res models themselves, which helped a lot in making the deadlines.'
That said, I'd expect ship models were indeed shared.