You probably already heard the update on WS2008 release to manufacturing (RTM), now scheduled for 1st quarter of 2008 instead of end of year 2007. As a result...

1. The transition exams 70-648 and 70-649 will be available on October 29, 2007, now. They were scheduled for September 20, but the changes/slip in technology mean some items on our exams are affected, too.
2. If you took the beta for either of these exams (71-648 or 71-649), your result should be available no later than October 29 (or a few weeks before).
3. The MCTS exams are still scheduled for RTM +30 days; the MCITP exams are still scheduled for RTM +60. Don't know what I'm talking about? Read about the WS2008 certification family.

Microsoft, Windows Server 2008, Windows Longhorn Server, RTM, Certifications

Source:? MSDN Blog