Finally after a lot of days, the Vista development team has announced on its blog that it is finished with the development of SP1 (Service Pack 1) and will be shortly giving it to partners and friends. The whole world will be able to get it through Windows Update and Microsoft Download Center in mid-March. So hold you horses for another month is what Microsoft means by this announcement.
If you have been following the leak, then you probably have already realize that it won't take another month to get it into your hands. The advantages that the Vista SP1 is supposed to bring is more under-the-hood in the form of stability, compatibility and performance improvements. You can read a well explained piece on what's changed with Vista SP1 on Paul Thurrot's website.
Vista SP1 is also an important update for Microsoft because quite a lot of people were holding their upgrade to Windows Vista from Windows XP until SP1 will be released. May be those people were expecting some more goodies and features like Microsoft has earlier provided with Windows XP SP2. But Unlike XP SP2, Windows Vista hasn't added new features to SP1. Even people who were expecting some Ultimate Extras to be shipping with SP1 will be in for some disappointment. Earlier Microsoft has hinted that people who bought Vista Ultimate would be provided regular Extras, but not much has been released after DreamScene, which is a animation/video desktop background.
Lets hope Microsoft will start working on some Ultimate Extras, now that they have stopped working on SP1.