With the debut of the GeForce 9600 GT, expect the GeForce 8800 GT and 8800 GS to slowly disappear. With its higher clock speeds and larger frame buffer, the 9600 GT is generally faster than the GeForce 8800 GT 256MB anyway, so FiringSquad doubt this GPU will be missed by many. Going forward they would like to see NVIDIA produce a more affordable G94 card with slower clocks (GeForce 9600 GS perhaps?), but for the time being the GeForce 8600 GTS will occupy the slot below the 9600 GT in NVIDIA's lineup. The GeForce 8800 GT 512MB will remain a viable alternative to the 9600 GT at the $230+ price point.
In any case, NVIDIA's truly got a winner with the GeForce 9600 GT. Whether you plan on purchasing one card or two, this GPU redefines what you typically expect out of a mainstream graphics card. Especially once the 9600 GT is overclocked.