It appears that NVidia have finalized the details and are about to launch their latest two chips in San Francisco this Wednesday. The NV38 and NV36, the call names of the two new models will, from now on, be known as the Geforce FX 5950 Ultra and the Geforce FX 5700, respectively.
The introduction of both of these boards aims to complete the NVidia range of high and mid end graphics cards.
The Geforce FX 5950 Ultra will feature 475MHz for the GPU and 950MHz memory, while GeForce FX 5700's GPU will speed by at 475MHz with 900MHz for memory, and a 128 bit interface. The 5950 is expected to be much faster than the current range of 5900's, although any imporovements will probably become more obvious after the Detonator 50x drivers launch, a beta version of which you can find in the Megagames software section.
Boards based on the chips should reach retail by October 26th.