Now that the latest Mac OS X version is available, the question is if you should rush into upgrading or not. Will your system and applications continue to work? And, more importantly, will Blender continue to work?
There's a thread on BlenderArtists where users report their experiences with the new operating system. So far, the verdict seems to be that Blender works just fine. With the upgraded OpenGL system the interaction is reported to be slightly faster.
Me? I still have some work to finish before I'll try the upgrade.