New CUDA 6.0 Release Candidate available

The CUDA 6 Release Candidate (RC) is now available to CUDA Registered Developers at
https://developer.nvidia.com/rdp/cuda-60-rc-toolkit-download
If you’re not already a member of the CUDA Registered Developer Program, apply today to start using new features like Unified Memory, Drop-in Libraries, and Multi-GPU Scaling in cuBLAS and cuFFT libraries.

You can sign up to become a member at:
https://developer.nvidia.com/registered-developer-programs

It looks like the new device driver is a requirement for the new features to work. I want to keep CUDA 5.5 as my development version and install cuda 6 on the side. Will cuda 5.5 work with the new device driver as before?

The new driver which is coming with 6.0 works fine with CUDA 5.5 for me.

When can we expect official CUDA6.0 release, especially for supporting Mac?