Many Vista owners want to test it
Microsoft has already released the Release Candidate Windows Vista Service Pack 1 via its Microsoft Connect service for the 15,000 people who have been involved in the Beta testing process since the start.
Now Microsoft will open the door a little wider with the addition of MSDN and TechNet subscribers that will also be able to have a look at the Release Candidate version of Vista Service Pack 1. Microsoft claims that they are still on track to deliver SP 1 for Vista early next year.