P/Cs are like cars of today, they are a loss from the time that you buy them, except P/Cs lose their value a lot faster than a quality car or truck that is well-mainained and has decent mileage.
That video card is 350 bucks now. I imagine it will come down even more as many people are thumbing their noses at Windows Vista and that was supposed to be the thing for DirectX10 (The 8800 is a DirectX10 capable card). I think they will come out with something eventually, but they will make sure us XP users do not get cold-cocked. IMHO. Nem would know more about all that technical stuff than I would.
Save your money and buy a 512 MB DDR2 card, it's almost half the price of that 8800 and is still considered high end hardware.