I don't know what is the real reason (copyright problems or decisions from Adobe?) but the feature that permits you to export and save files as PDF or XPS format (announced firstly to be integrated into Office 2007 and then to be removed) is now available as a separate download from Microsoft.
Having it as a separate add-in is not so nice but what is really important is finally to have this feature integrated into the Office system (so no needs for external tools). Nice... 