Leggo e cito dal sito http://technet.microsoft.com/ a questo indirizzo:

Windows Vista Service Pack 1 is an update to Windows Vista that addresses feedback from our customers. In addition to previously released updates, SP1 contains changes focused on addressing specific reliability and performance issues, supporting new types of hardware, and adding support for several emerging standards. Windows Vista SP1 also addresses some management, deployment, and support challenges.

On February 4, 2008 Windows Vista Service Pack 1 was released to manufacturing.  TechNet Plus subscribers can now access Windows Vista SP1 in the Top Subscribers Download section on the subscriptions home page.  Windows Vista SP1 will be available to the public in mid-March via Windows Update and the Microsoft Download Center.

Ergo quanto riportato, da me, qui non è attendibile!