This is great for making older graphics cards have uses, no longer do we ditch our old when upgrading we drop it down to the Physics processor then when we upgrade again odds are the physics board will be worth considerbly less. More bang for your buck!
Also related documentation I found whilst looking up what ATI has said about their boards and physics in the past can be found
here. Aperntly ATI is/has released an API that lets developers access the R5XXX and R6XXX cards with out having to go through OpenGL or DirectX, this is a great step forward in allowing people to use their video card for MUCH MUCH more then just displaying graphics. Imagen folding on your Video card when you are not running in 3d mode!
I think this is a large step for ATI in making their cards more "upgrade" proof then nVidia, and personaly that is worth more then 10-15 more fps.