NVIDIA has released an updated driver for Mac OSX Lion 10.7.3. It can be downloaded at:
The good news is this update seems to provide CUDA support on OS X for all CUDA capable NVIDIA cards including the GTX580.
We have tested this and it works well for Resolve on Mac OS X.
We were using a configuration with 3 x GTX 580 on a Cubix Desktop 4 with a GT120 GUI GPU, and we could get 25 nodes of image blur processing at 24fps, or 4 nodes of noise reduction at the default settings.