He says this mod will further improve the already impressive graphics of this game. The mod adds:
The overall graphics quality should vastly improve with this mod and best of all, it doesn't cost you any framerates. According to the details your FPS may even improve by up to 20 percent.
Full reflection vector calculations Better bump mapping Real specular effects Better shadow effects - no longer jagged but soft
More info and download over here. Unfortunately there are no screenshots available yet.