The Genius Sidebar will introduce you to new music, movies and TV shows youll like. As you select media in your library, the Genius sidebar displays media from the iTunes Store that go great with it. You can preview and buy recommended media directly from the sidebar.
For some reason Apple decided to pull the Genius feature from video files just before the release of iTunes 8.1 a few weeks ago. Reports are coming in that the Genius iTunes Store recommendations for Movies and TV Shows have suddenly started to show up.