Just stay tuned, the fully fledged Release Candidate built for Windows Vista Service Pack 1 is almost here. In fact, Microsoft is gearing up to make the announcement about the availability of Vista SP1 RC. This way, the Redmond company will move the first service pack for Vista out of RC preview stage. Vista SP1 RC has been planed to drop any day now, since earlier this week, with Microsoft delivering all the right indications of the RC build's imminent release, but the wait is nearly over. Later today, the company will announce the availability of Windows Vista SP1 RC.

The most recent release of the refresh has been Windows Vista Service Pack 1 Release Candidate build 6001.17042 delivered in mid November to some 15,000 testers. Internally, Microsoft moved up to build 17051 toward the end of November, but little transpired of the company's upcoming plans, except indicators of the proximity of the RC build. The Redmond company failed in disclosing the version of the Vista SP1 development milestone achieved internally, but did hint that December would bring the next stage in the evolution of the service pack.

This week, Microsoft has also made available the first Release Candidate of Windows XP Service Pack 3 to all subscribers of the Microsoft Developer Network and TechNet. In this context, it is clear that the RC for Vista is not far behind, the two service packs have been virtually joined at the hip, ever since they have initially been introduced in mid July 2007. No word yet from Microsoft regarding Vista SP1 RC taking the same path as XP SP3 RC via MSDN and TechNet, although this is the most likely evolution of the service pack. Still, a public version of Vista is also expected to hit in December. And on top of it all, as Paul Thurrott reported, Vista SP1 RC would be accompanied by the Release Candidate 1 of Windows Server 2008, formerly codenamed Longhorn.