Windows 8 and Skydrive has a similar concept built into it called contracts. Developers can integrate their app to work with Windows 8's UI. For example you can search your Flikr or Facebook directly in the OS in the same way that you search the file system.

Here's a video demonstration: http://www.youtube.com/watch?v=Hesj1I_wsqI#t=12m00s

http://blogs.msdn.com/b/windowsappdev/archive/2012/03/23/act...