No one has made killmoves. All kill moves currently added as mods where already in the game but disabled. Adding Animations is really tricky right now, there is no easy way to do it. Progress is being made but it will take time. On top of that ripping AC moves would be illegal, even though AC looks awesome. If the animation problem gets fixed it would be cool if we could import The Witcher animations and convert them to the skyrim rig.. but I believe it will be difficult, very difficult if possible at all.