Go to the link for all the concept arts, all beautifully made by ChaoyuanXu from Deviant Art.
It would be absolutely perfect, the culture, the story, there is so much potential. Plus there is the use of martial arts, it could be a great Assassin's Creed game. Well, only if Ubisoft doesn't mess it up (if they ever do end up making it). Come on Ubisoft, there is no viable reason NOT to make an AC game set in Asia.