WinFS includes support for synchronization with external data.
WinFS Sync provides developers with a set of API's that allow for synchronizing with other WinFS stores (i.e. on other computers), as well as with connected devices like a mobile phone, or with Web services such as a web-mail server.
WinFS Sync handles all the detail-work related to conflict detection, resolution, and error-reporting. This should allow Sync adapter developers to focus on mapping their data to WinFS as accurately as possible.