Apple had announced during at the iPhone 5 special announcement event in September that it will be releasing iTunes 11 soon, after few weeks of delay September, iTunes 11 was officially launched by Apple to the public today.
Apple has worked towards getting rid of the additional clutter. They have removed the the sidebar, the store window, lists of playlists and other extraneous information.
Library views drill down to the content type you’re after, and only that content, switching entirely for music, TV shows, apps and movies, and bringing sub navigation to the top of the interface.