Activewin.com have updated their Windows 2000 Service Pack 3 Bug Fix list. Here's a short desription.

The list includes the KB # and the full description for every bug, unlike the old list which had some listed as N/A. There are several hundred listed.

And they also have the release notes for Windows 2000 Service Pack 3 Beta.

ActiveWin.com: Windows 2000 SP 3 KB Bugs Fix List - Updated

Windows 2000 Service Pack 3 Beta Release Notes