NV41 is Geforce 6700@ 2004/10/20
This chip will be clocked at 400MHz while the memory on cards will work at 1000MHz. You will be able to buy 128MB and 256MB versions.
NV41 is derived from NV40 and will have full support for Pixel Shader 3.0 and at this time it's PCIe only. Those cards are set for production in November