I have already written about that, but now, Part 3 is available as well:
http://www.windowsecurity.com/articles/Group-Policy-related-changes-Windows-Server-2008-Part3.html

Group Policy related changes in Windows Server 2008
WindowsSecurity.com article from Jakob H. Heidelberg on GPO stuff in Windows Server 2008:

http://www.windowsecurity.com/articles/Group-Policy-related-changes-Windows-Server-2008-Part1.html
http://www.windowsecurity.com/articles/Group-Policy-related-changes-Windows-Server-2008-Part2.html

Urs