Mockup for Integrated Music Playback in Nautilus

Just browsing through DeviantART, I found this mockup by vincentpsp2 that integrates music control and playback in Nautilus itself.

Please expand the image to better understand the number markers explained below:

1. Music Button for Nautilus to go in enhanced mode with playlists and controls
2. Easy music playback control from the navigation bar
3. Playlists works with popular music players like Rhythmbox and Amarok with native notifications support. Playback continues even if you leave the nautilus window.
4. Clicking on the music button brings back Nautilus to normal Mode
5. In normal mode, you will only see album cover, album title, song title and artist name of the selected song in playlists

There is something though that is not clear to me: The playlist support is only for music players or it will automatically track the nautilus folders and make a playlist from it?? The later feature can be really useful. The original page was in French and I translated it using Google Translate. So I may have missed something.

So, what do you think about the mockup?