I haven't seen it reported elsewhere on the net, but now that Mountain Lion (10.8) has been released, here is the OpenGL version info for the Core profile:
[OpenGL Renderer] NVIDIA GeForce 8600M GT OpenGL Engine
[OpenGL Vendor] NVIDIA Corporation
[OpenGL Version] 3.2 NVIDIA-8.0.51
[OpenGL Profile] Core
[OpenGL Shading Language] 1.50
Effectively, no change compared to Lion on this MBP.