First thing we need to do is verify that the image quality between ATI Radeon and NVIDIA GeForce cards are the same so we can objectively measure performance.
Now looking closely you'll notice a little color-tone difference. This scene has a lot of volumetric fog consistently moving from the right to left, which is the cause of that color tone difference. You can actually see that if you look at the end of the road and then compare with the Radeon shot. The reality is that there is very little difference to spot with the naked eye. The one thing we did notice was that ATI's shadows and also textures seem a little darker. The ATI cards might have a slightly difference contrast somehow.
I also took the liberty of taking a few screenshots for you guys, COD World at War is loaded with fire, flamethrowers, Molotov cocktails. The enemy running around lit on fire .. it's pretty nasty really.
Loads of vegetation, objects, threes, motion blur. Though the game uses the older COD4 engine, it's still capable of some amazing stuff.