I hope they improved the clothing textures. In AC:R, there were some cutscenes that zoomed in on the clothing and it was all 'fuzzy'.
Even if the graphics were not changed, we PC gamers get more tessellation + other DX11 options .
I also hope they do the animation justice. In AC:R, I feel as if they just added masks to the Assassins and moved the camera angles to behind characters so they did not have to animate the facial features.