Yes, the 7900GS that will be coming out is the desktop variant, and is rumored to have 20 Pixel Pipelines versus the 24 on the GT. Dell is already offering them with their XPS computers. The cost of the 7900GS SLi is $250 more than a single card, so prices for the GS can be expected to fall around $250, and may drop to the $220s or lower with future rebates.
Also I see no real point for the 7600GTX, unless they can price them at under $200.
Also, the 7900GS for $250 is still overpriced considering that a new X1800XT 256mb can be had for $239 with NO REBATES at Newegg.