According to tech news site Daily Tech, amongst others, the GeForce 8500 GT, GeForce 8600 GT and GeForce 8600 GTS will launch on April 17, with the GeForce 8300 GS and GeForce 8400 GS following soon after.
The specs of the first three to be released are as follows:
GeForce 8600 GTS -- 256 MB GDDR3, 675 MHz core clock, 1000 MHz memory clock
GeForce 8600 GT -- 256 MB GDDR3, 540 MHz core clock, 700 MHz memory clock
GeForce 8500 GT -- 128 to 256 MB DDR2 or GDDR3, 450 MHz core clock, 700 MHz memory clock
The 8600 GTS is expected to cost around $200, the 8600 GT around $150 and the 8500 GT around $100. Nvidia expects all three cards to be available at launch, while the two lower end ones are expected to be primarily OEM models.