just spotted this on a few blogs..
http://www.microsoft.com/downloads/en/resultsForCategory.aspx?nr=50&sortOrder=Descending&sortCriteria=Date&period=30&stype=ss_nd&sterm=All+Categories
and the extract from the ms site
Service Pack 2 (SP2) for Windows Server 2008 and Windows Vista is an upcoming update to Windows Vista and Windows Server 2008. It will provide customer and partner feedback-driven fixes into a single service pack, minimizing deployment and testing complexity. In addition to all previously released updates since SP1, SP2 will support new types of hardware, and will add support for several emerging standards.
As of April 28th, 2009 the Windows Server 2008 SP2 and Windows Vista SP2 Beta program has concluded, thank you for your participation and feedback.