no... only the nV's 8xxx and AMD's 3xxx and 2xxx series cards utilize dx 10. Like mentions above, anything below this is dx9. Additionally you need the 8 series, 3 and 2 series to run in vista.
no. this is false.
partially..... and misleading.
you do not need a dx10 card to A. use vista , or B. play games in vista.
you just need a dx10 card, to utilize dx10.
so essentially, you will still be playing games with that card, you just wont be able to access the same special effects that are available in dx10.