What's up with "Configure Windows Activation"?
The reviewers guide talks about Windows Activation Service and Windows Process Activation Service as if it is one thing. Search through the guide on WAS and WPAS (search case-sensitive, was is a pretty common word ;)). Now it could be that this is important, because from what I remember from the things I read on one of the links below, IIS7 is a very major topic. However, I still feel it's that nasty Windows Product Activation that is featured under "Configure Windows Activation". This feeling is based on the location in the prep-guide and this line in the reviewers guide.
In addition, because product activation can be done within a grace period (typically 30 days), and is not critical for the initial configuration of the server, the Activate Your Server command, present on the Manage Your Server window in Windows Server 2003, has been removed from Initial Configuration Tasks.
That's however all I found on product activationin the reviewer guide (maybe that, and how to invoke activation after deployment is all you need to know on the exam).
Experiences from others on 70-649 in general:
http://www.mcseboard.de/mcse-forum-pruefungen-33/mcse-mcsa-upgrade-2008-beta-pruefungen-117512.html (German; forum which had already 3 pages in the thread when I checked)
http://www.techlog.org/archive/2007/06/08/windows_server_2008_upgrade_ex
http://blogs.infosupport.com/ericd/archive/2007/07/17/Exam-70_2D00_649.aspx
http://blog.tiensivu.com/aaron/archives/1171-Took-71-649-will-be-70-649-today-Upgrading-MCSE-2003-to-2008.html