Microsoft touts performance and reliability as the key benefits of Vista's SP1, but a close look at the beta shows a significant change Microsoft doesn't seem to want you to know about --- you can now easily change your default desktop search tool to Google Desktop Search, or any another one.
As I point out in my review of the beta of SP1, SP1 makes several interface changes related to search. The Start menu's Search link has been taken away, and if you choose Start --> Default Programs --> Set your default program, you can easily change your default search to any tool you want. As I show in my review, there are several other changes related to search as well.
Those changes were not made willingly. Microsoft made them as an extension of the company's 2002 antitrust settlement with government regulators.
But in briefings Microsoft gave to the press, PointPoint presentations, and a white paper about SP1, Microsoft made no mention of the change, even though the company presented in exquisite detail many other much more minor changes that SP1 makes.