From this interview:
This says, to me, that the NV31 and NV34 products will support the same basic programmability as the NV30 (though perhaps with different instruction length support).Q: For the past couple of years, NVIDIA has had a very diverse product line for each generation, offering a card worthy of each users unique needs. The number of available cards at one given time has indeed fluctuated here and there. Will the FX series be a more simple offering of products or eventually broader than we've ever seen?
A: I can’t discuss unannounced products, but I can say that the CineFX engine at the heart of the GeForce FX architecture was designed to be highly scaleable in nature and gives NVIDIA the ability to quickly execute on a top-to-bottom product family that all share the same basis feature set and address a variety of segments with different performance level and price points.