If you work with Desktop Group Policies at all (including IE settings), you would be interested in these two reference documents.
In response to customers need to make the OS and IE more manageable, Microsoft has significantly increased the number of policy settings in Windows XP SP2. Numerous additional aspects of the OS are now policy-enabled, while many of the other policy settings are zone-based groupings of similar settings for a significantly more manageable IE.
Windows XP SP2 provides more than 600 new Group Policy settings to help administrators manage policy settings related to Windows Firewall, Internet Explorer, Internet Communication Management, Automatic Updates, security, Terminal Services, user profiles, and other network-related features. This white paper includes information to help administrators assess, deploy, and use the new Group Policy settings delivered with SP2.
Group Policy Settings Reference for .adm files included with Windows XP Professional Service Pack 2
This spreadsheet lists the full set of Group Policy settings described in Administrative Template (.adm) files shipped with Windows Professional Service Pack 2. This includes all policy settings supported on Windows 2000 (to Service Pack 4), Windows XP Professional (to Service Pack 2) and Windows Server 2003. The spreadsheet includes separate worksheets for each of the .adm files shipped, as well as a consolidated worksheet for easy searching. Additionally, an "Update History" worksheet has been added to list those policy settings added since Windows Server 2003 was released. Using column filters, the spreadsheet allows simple filtering by operating system, component and machine/user configuration, as well as regular text search of keywords through Excel.