If-This-Then-That (IFTTT) integration could be cool. You could expose playlists to IFTTT as either triggers and/or actions. Use cases could be when a certain playlist is started trigger lights (via WeMo or Hue). So for lighting, a "Dinner" playlist could set a particular light pattern via Hue, or turn off some lights and dim others. You could also start a playlist when motion is detected via a WeMo motion detector, or when a switch is turned on, start a playlist. You could use a special playlist to provide a house-wide audio notifier of new emails, Facebook/Twitter/app.net mentions, or Google Calendar events.