Yes you can do it. It's more dependent on the video card and it's drivers. It's not a funtion of the OS. I recomend you wait for the full release verion of Vista. I've been seeing peopel having problems getting to some of the exstra features of there video cards useing the pre release version of vista.
I really don't think you know what you're talking about because according to Nvidia's website, it IS a function of vista, and it WILL NOT be supported by any sort of nvidia driver. (i read this in the nvidia vista driver release documentation.)
thanks for trying though...i thought the same thing as you until i read that.