Cg Release 1.3 Beta 2 has been released with support for the latest GeForce 6 Series (NV4X) GPUs. This version of Cg offers the following features and improvements:

• New vp40 profile, which enables texture sampling from within vertex programs
• New fp40 profile, which provides a robust branching model in fragment programs, and support for output to multiple draw buffers (“MRTs”)
• Support for writing more than one color output (i.e., MRTs) in the arbfp1 and ps_2* profiles
• New semantics to access OpenGL fixed-function state vectors from within ARB_vertex_program and ARB_fragment_program
• New “-fastprecision” option for arbfp*, fp30, and fp40 profiles, to use reduced precision storage (fp16) when appropriate
• Support for 16 profiles

(http://developer.nvidia.com/object/cg_toolkit.html)