In the new Skyrim demo, everything looked outstanding but something I didnt like was the rain effects. Its basically just an overlay on your screen. They rain should be in 3 dimensions, kind of hard to explain.

Even Minecraft does it right.
http://www.youtube.com/watch?v=qy882ILYJMM&feature=relmfu

If you move forward you see the rain move towards you. Its a real 3D object