The key here is that the GeForce2 MX, which had the full featureset of the GeForce2, carried the NV11 name. The GeForce4 MX, also of GeForce2 technology, carried the NV17 name.
The upcoming low-cost part (NV34) is an NV3x part. nVidia has not yet watered down the programmability of any part within a family.
This doesn't absolutely guarantee that the NV34 will have the full programmability of the NV30, but it comes close to it (I think it may have a few "lesser" functions removed...such as high-precision log/exp/sin/cos).
"Physics is like sex. Sure, it may give some practical results, but that's not why we do it." - Richard P. Feynman