What it looks like
Futuremark have some comparison images that show you the differences in render output in 05 and 06, in the graphics tests that are carried over. Here are a few to peek at before you go off and download it and see for yourself. Even the SM2.0 tests get the update treatment, remember.You can see the new lighting system in action in the first shot with the new filtering of shadow edges quite clear. The second shot is a dramatic highlight of the new ShaderModel 3.0 rendering engine in what used to be Game Test 3. Image three shows you the shadowing and art asset update in the SM2.0 firefly test, and the green fly's new pink friend.
This shot from the brand new second SM3 test, Deep Freeze, shows off the new 'HDR' lighting system.