I would avoid the card you're looking at right now. I really think that it would be a waste of your money to buy this card, just because of DX10.
Just because the card is a "DX10" card, doesn't neccessarily mean that it'll play them well. (I would imagine that an 8500GT would be out performed in DX9 games by other DX9 only cards, how much better (or worse) would it perform in a more graphically intense DX10 game when they come out?
If you want a DX10 card make it worth you while and buy one that has the raw power to play the future DX10 games.