From the Alias website:
The Mac community has repeatedly asked us for the same award-winning Maya Unlimited software currently only available for Windows, Irix and Linux operating systems, and we have listened. Now, thanks to your unwavering support for the effort, we are happy to announce that Maya Unlimited will soon be available for Mac OS X.
Mac artists were the driving force that persuaded Alias to first launch Maya Complete for Mac OS X and the demand for Unlimited on this platform has been steadily growing ever since. Maya Unlimited is well worth the wait: the world