According to the official Google blog (http://googleblog.blogspot.com/2006/01/google-earth-in-mac-world-pc-too.html), they just released Google Earth for Macs. It's also no longer in beta!

The link got botched since I didn't leave a space at the end: http://googleblog.blogspot.com/2006/01/google-earth-in-mac-world-pc-too.html