Let get this out of the way, you are wrong...
haystack15 :I think they should because Direct X 10 is made for windows vista for game compatibly.
DirectX is backwards compatible between versions.
It also is a basic power manager for game frame rate. So you won't kill you computer power.
There is no such thing as a 'power manager for game frame rate' the frame rate is a product of the GPUs ability to render, the motherboard, memory and HDD's speed in feeding the card information and display drivers efficiency orchestrating the process. All DirectX does is provide a consistent interface and set of features to developers to allow them to develop a single code-base that targets all GPUs.
I just hope that because they won't move to it that Arma2 will have frame rate problems leading to crashing or blue screens on windows Vista users. :|:|
Unless you have crap hardware there is no reason that this should happen.