WinFS Availability
Early Windows Longhorn & Windows Vista WinFS Builds
WinFS made its first appearance as an optional component in the Windows "Longhorn" builds that Microsoft was producing internally through most of 2003. At the Microsoft Professional Developers Conference that year, the first build of "Longhorn" was given to developers. This became known as the "PDC Build", or Build 4051.
The general consensus from developers and reviewers was that WinFS was unusable due to excessive memory requirements, unfriendly and under-documented developer API's, and no clear indication on how it was actually going to improve the day-to-day Windows user experience. In August 2004, Microsoft announced that WinFS would not ship with "Longhorn".
Latest Release and Future Development
After a full year of silence from Microsoft, WinFS Beta 1 was made available to MSDN Subscribers on August 29, 2005. (Beta 1 was refreshed with no new features on December 1, 2005 to be compatible with the final release of the .NET Framework v.2.0). Microsoft has a commitment to back-port WinFS to Windows XP and 2003, and to make it available as an installable component in the same way that the .NET Framework itself is. Beta 1 only supports Windows XP with Service Pack 2.
Beta 2 is planned for May 1, 2006. It will include integration with Windows Desktop Search, so that search results will include results from both regular NTFS files and WinFS-backed files.
A third Beta is planned for November, 2006.
The final release will most likely not be available until late 2007. The final release of WinFS will not be included with Vista and whether it will be included in Longhorn Server or not is not clear at this time.