Oh I see... you're trying to collapse the left panel as permanently as possible and have all the important nodes loaded into tabs instead.
I guess I'd use a 'playlist node' if the option was there in the playlist pane. However, the view would be useless if all the playlists were just mixed together and ordered alphabetically. It would have to take account of the folder structure of the playlists and group them accordingly.
Also, I can't quite imagine how the UI would work. At the moment when you browse your lists in the left pane, the playlists load (or are generated in the case of autoplaylists) in the main panel. But if you've got this new playlist view in the main panel, presumably when you click a playlist, the playlist view would disappear and be replaced by the playlist itself: you'd need to keep pressing the back button to get back to the playlist view.
Not sure I'd want to rely on tabs as much as you guys seem to be doing.