The 7600GT will more than likely NOT support DX10 (as I see it its a definate NO, but the qualifications are still in debate) Neither will most if not ALL of the cards that are out today, but there has been talk that the high end cards (1900XTX, 7900GT/GTX, 7950 etc) being able to, but we dont know for sure yet.
The r600 and G80 (also known as the r580) are the new cards coming out from ati, and the r600 is the first card that is DEFINATLY DX10 compatible. These are both high end cards and will probally be priced around and above $400 depending on the model.
the 7800gt is sli capible
DFI infinity RS 482
3Gig Corsair PC 3200
AMD X2 4400+ 2.4ghz
250Gig Samsung SATA 3.0 7200rpm
250Gig Hatachi SATA 3.0 7200 rpm
60Gig Maxtor ATA 5400 rpm
2x160Gig WD SATA 7200 rpm RAID-0
ATI X850XT 256mb
Antec TruePower 430