Windows Vista SP1 available to WSUS
Quick update on Windows Vista SP1’s availability to Windows SUS. As I mentioned previously, we are planning on making the full standalone version of the service pack directly available to WSUS shortly. Before we do so, we would like to give you one last reminder to install the WinVerifyTrust update if you are running your WSUS server on a Windows 2003 Server or else approving SP1 will result in the binary being continually re-downloaded to the Server.
WSUS Product Team Blog : Windows Vista SP1 available to WSUS