Hot off the press, Apple just released Mac OS X 10.4.11, otherwise a minor update to the last OS release. I haven't upgraded to PantherCheetahLionLeopard yet (since Yale has a site license and I have to wait until I'm back in the USA) -- but the big thing about 10.4.11 is that it supports the Microsoft Presenter Mouse 8000 -- which I've blogged about before.
Yippee! Keynote here I come!
For more: http://docs.info.apple.com/article.html?artnum=306297