The wait is nearly over for the first service pack for Windows Vista, according to sources close to Microsoft.

Microsoft has said the highly anticipated service pack would be out in the first quarter of this year, but some say it could be available in the next few weeks, more than a month before the quarter ends on March 31.

A Taiwanese news outlet Wednesday reported in a story that Vista SP1 would be released Feb. 15, but "that date is as good as any other," an analyst with Directions on Microsoft, Michael Cherry, said. "For all we know, they could make it available tomorrow."

Through its public relations agency Wednesday, Microsoft declined to comment on the Feb. 15 date beyond reiterating the software would be available in the first quarter. Still, several sources who work closely with Microsoft said a mid-February release is not unlikely, and they expect the software to be out before the end of March.

Director of software industry analysis for the NPD Group, Chris Swenson, said that analysts have heard Feb. 15 as the target for SP1, but it's not something Microsoft would confirm publicly to give itself time to make adjustments in case of negative feedback on the current release of the software.

Microsoft released Vista SP1 Release Candidate (RC) in December, but then refreshed that software in a public release earlier this month.

Several Microsoft partners said they could not confirm Feb. 15 as the date for SP1's release, but said they expect the software soon for a number of reasons.

One of those is the strength of the release candidate, a senior consultant with MCW Technologies, Brian Randell, said. He has been using the SP1 RC and it's stable and running well so, "I can't see why [the final release] wouldn't be out soon."

Microsoft's hesitancy to give a firm date for SP1 means the company is confident it can get the final release out on time, said Andrew Brust, chief, new technology for consulting firm twentysix New York. However, he agreed with NPD's Swenson that the company wants to give itself room for last-minute changes. "They are not ready to promise anything beyond Q1," he said. Brust is a regional director of Microsoft partners and works closely with the company.

Many believe the SP1 milestone is the one that will bring about a new wave of adoption for Vista, especially among business customers that have been awaiting the service pack's release before updating employee desktops. The combination of SP1 and Windows Server 2008, due out on Feb. 27, is expected to bode well for Vista adoption in the enterprise and medium-sized business sectors.

One date Cherry said Microsoft probably won't release SP1 is the next Patch Tuesday, Feb. 12. Patch Tuesday refers to the second Tuesday of every month when Microsoft sends out software patches and updates via its automatic updating services.

"Hopefully, they would keep the release of monthly patches separate from the release of a service pack," Cherry said.