I have only tested 4.7 for a very short time, but what i have seen:
In 4.7 the playlist-list is shown in the left frame.
If you click on a playlist, you see the tracks in the main frame (like an album view).
You then have the possibility to play/add the whole playlist, or just some tracks.
You can also move and remove specific tracks from the playlist.
And there is the sharing feature. Playlists are private by default (only visible and changeable by the creator), but the playlist can be made public (visible to all users, changeable by the creator and admins).
What i liked about these changes, is that you can view/browse the playlist before actually having to load the list (in 4.6 you don't know what exactly you are loading). Plus picking selective songs to add to the player is nice.