For the most part, they function the same. There are only a couple of things to keep in mind:

1) Maya plug-ins are platform-specific. If you use any 3rd party and/or custom plug-ins, they must be compiled specifically to work in the Mac version of Maya.

2) A universal binary version of Maya has not been released for the current Intel Macs. The current version will run ok on the Intel Macs, but it won't be as fast as it could be. Rumors have it that the next release of Maya will be Universal. No confirmation yet.

Other than that, Maya is the same on all platforms. Sounds like for what you want to do, you should have no problems switching to the Mac version of Maya.