Microsoft has updated the Windows Service Pack Blocker Tool Kit to include Service Pack 1 for Windows 7 and Windows Server 2008 R2. As has been the case with previous service packs, soon after SP1 hits the RTM milestone, it will first go out on Windows Update (WU), and then eventually Microsoft will push it out via Automatic Updates (AU).
Users who don't want SP1 will be able to simply disable AU. Many businesses, however, prefer to keep AU on, but block the service pack so they can first test to make sure it works with all their software. The service pack blocker will allow them to continue having Windows 7 and Windows Server 2008 R2 update automatically without SP1. The tool is valid for 12 months following general availability of the service pack. After that, Microsoft will push out SP1 to everyone with AU on, regardless of whether it has been blocked.
The tool kit consists of three components: a Microsoft-signed executable, a script, and an ADM template. All of them set or clear a specific registry key that is used to detect and block the Service Pack download from WU. Companies can choose the one that works best with their computer management infrastructure.
Microsoft released the Release Candidate (RC) of SP1 for Windows 7 and Windows Server 2008 R2 SP1, two weeks ago. Microsoft says it expects to release the final version of SP1 in the first quarter of 2011. Microsoft typically updates the Service Pack Blocker Tool Kit two months before a service pack's release. If Microsoft sticks to this timeline, we can expect SP1 in January 2011.
Source: ars technica