This was posted by Joe Defuria over at beyond3d. I think it pretty much sums up why this is a cheat and not an optimization even though image quality stays the same so I'll just paste that quote here:
Referring to this as an "optimization" or a "cheat" is all ultimately semantics. Even Futuremark doesn't seem to be consisent about how to "accurately" run the 3dmark program (read above about how they allow overclocked graphics cards and cpu's, but not non-WHQL drivers). Also, NVIDIA doesn't have authorized access to the developer's version of 3dmark03 while ATI does. All of this practically throws normalization of the benchmark out the window.