Running OS X 10.10.2 with 3rd security patch, can't remember build number off the top of my head, although it's the one that corresponded to the 343.02.02 release. The os build has not changed since then. The dual EVGA GTX 970's (one SC and one FTW) were running just fine under the 343.02.02 drivers (march 23 release) and then the pref pane came up telling me new ones had been downloaded, so I installed. That was a bit odd as from what I've seen recently they only release new drivers when Apple OS updates change the build #. On relaunch none of the CUDA stuff worked. CudaX said "no cuda devices available". Blender couldn't fine the GPU's either. So I reinstalled the 343.02.02 drivers and am back and running. Just a heads up, before installing you may want to have the previous version available in case you have problems. No idea why they broke, but they did.