Long press music controls

Long press play button: shuffle or add track to library or user configurable to something else.
Long press previous track button : skip back 15 seconds or user configurable.
Long press next track button: skip forward 15 seconds or user configurable.

Loads of other long press actions could be defined.

In the playlist when you press the play button on the track listing it plays the track, pressing it again to pause the track would be nice.

Anyway, just an idea.