One of the most exciting and interesting new features to be included in Longhorn/Windows Vista, but removed from the list of new features some time back, was the planned inclusion of a new file system, named WinFS, that was to replace the hierarchical file structure that we have lived with in Windows since MS-DOS.
WinFS was supposed to be a radical departure from current file system thinking, where application data (files) would be stored and managed by a database engine.
Well, according to this blog entry by the WinFS team, not only will WinFS not ship as an included component of Windows Vista, it is now no longer being developed as a Windows conponent as an optional add-on. Development has shifted and it may now find itself integrated into SQL Server.