"The other significant part of the Windows UI is Explorer. Windows 7 introduces a new concept named Libraries. Libraries provide a view onto arbitrary parts of the filesystem with organization optimized for different kinds of files. In use, Libraries feel like a kind of WinFS-lite; they don't have the complex database system underneath, but they do retain the idea of a custom view of your files that's independent of where the files are."

OOh, I do like Libraries. One of the things they wanted to do in Vista and left out.