nVidia has just released a new GPU for the forgotten connector, AGP. The GeForce 7800 GS is based on the same technology as the 7800 GTX, just a little cut-down in the features department - pixel shaders are down to 16 from 24 and vertex shaders are down to 6 from 8.
Here is some coverage around the web via the below links.
Now, the reasons for this hack job on the G70 GPU could be several. Sometimes, a portion of a chip just doesn't come out working properly, but the GPU can still be used in a partial configuration like this one. It's possible NVIDIA has a load of G70 chips sitting in a warehouse somewhere that aren't quite up to the task of acting like a full 7800 GTX. Other times, chipmakers deactivate portions of a chip purely for product segmentation reasons. We really like the GeForce 7800 GT, another partially realized G70 product, because it's a better value for the money than the full GTX. In the case of the GeForce 7800 GS, NVIDIA's motivations for cutting down the G70 to a 6 vertex shader/16 pixel shader/8 ROPs config may be some combination of a desire to move chips that aren't 100% perfect and an intention to meet the needs of a lower-end market. I dunno.