Thanks to Iyaz Allah Baksh for sending out this great summary of WSS SP2. Note that some links may not be live yet, but will be soon.
The WSS SP 2 release has substantial supportability improvements including,
– Support for running on 64-bit machines in 32-bit emulation mode
– Support for Reverse Proxy and Alternate URL support
– Support for IP Bound virtual servers
– Support for off-box SSL termination
– Support for SQL Server 2005
– Support for ASP.NET 2.0
All customers (WSS and SPS) are encouraged to update to WSS SP 2. However, although SPS SP1/RTM will be able to run on top of WSS SP2, we are restricting support for the “shared” functionality that is added in SP2 for SPS and WSS until SPS SP2 ships. The shared functionality is the support improvements above. This information will be explained in both the WSS SP 2 press release and in KB http://support.microsoft.com/?id=887624 (description of WSS SP 2)
A couple of useful KB articles,
http://support.microsoft.com/?id=887624 Description of WSS SP 2
http://support.microsoft.com/?id=906336 WSS SP 2 KB article listing all of the fixes
http://support.microsoft.com/?id=875358 Guidance for deploying WSS SP 2 including the new SP 2 version number
http://support.microsoft.com/?id=832769 will be updated to reflect that SP 2 now enables Kerberos out of box. The one main addition in the article is how to switch back to to NTLM if you accidentally chose Kerberos and it was not what you wanted. If you chose Kerberos and did not configure the SPN then your users will not be able to autheticate to the SharePoint site.
http://support.microsoft.com/?id=894903 when switching a WSS virtual server from ASP.NET 1.0 to ASP.NET 2.0 you need to run an stsadm.exe operation to update web.config for new ASP.NET 2.0 security settings
The Windows SharePoint Services Administration Guide should also be updated later in the day . Make sure to download the latest copy so that you have instructions for using the new WSS SP 2 feature functionality.
Live version on Technet, http://www.microsoft.com/resources/documentation/wss/2/all/adminguide/en-us/default.mspx
Windows SharePoint Services SP 2 will also ship in Windows Server R2. Additional documentation about the new SP 2 features is included in this walkthrough document, http://www.microsoft.com/downloads/details.aspx?familyid=abba20f2-3625-4c9c-a412-ab9bbebdb5e8&displaylang=en.