The problem is that about two years after a 3dmark version comes out, all the video cards start to get the same scores due to CPU limitations. It has happened very quickly with 05 due to the emergence of dual card setups and generally the amazing rate at which video cards have grown faster since 05's release. For example, two 7800GTs, two X1800XTs and two 512MB 7800GTXs all score within 1000 points of each other in 05 despite their real performance being very different. So they have to keep changing the thing in order to keep up with newer games and make the differences show up.
I think this is going to happen even faster with this new 06 version, as the best current video card setups are already breaking 10k with it and there are much faster cards coming out very soon. The X1900 line will launch this Monday and G71 is reported to come out in early March.