I've been having a few teething issues with the OSX version; these included creating a 32 bit version instead of a Universal version. That then got updated into a Unity 4.3.4 build, but THAT was crashing in Darwin - so, finally, there's been a big update, and the Mac version is now shiny and brand new, and using Unity 4.6.9. You lucky, lucky Mac owners.
As a primary PC gamer, most of the things I said in the previous sentence are just words I don't really understand, so here's a picture of my cat being annoying to finish up with.