WinFS which was orginally to be a component of the Windows Operating system (originally Vista, then Vista Server...) , then was to be a stand alone update to the OS, is now reported to now no longer be a stand alone component but instead a feature of the next version of SQL Server:
Other technical work in the WinFS project is at a similar point specifically the integration of unstructured data into the relational database, and automation innovations that make the database "just work" with no DBAs “ "richer store" work. It's these storage innovations that have matured to the point where we are ready to start working on including them in our broader database product. We are choosing now to take the unstructured data support and auto-admin work and deliver it in the next release of MS SQL Server, codenamed Katmai (more)