Cliffnotes: Connect360 is a $20 program that installs on your mac and works with your xbox 360 allowing the flow of media onto your 360 to view.
Late September 2008 release: v3.36
What's new in V3.36?
* Fixes "Share only checked photos"
* Fixes playcount updates to be more accurate
* Added setting to limit the refresh interval for iTunes
* Fixes incompatibility with MediaLink, update MediaLink too
* Mac OS X 10.4 or later is now required