I've been asking for ages for a few different feature options for the up/down and left/right album art swipe actions. Currently it's just an on/off toggle for track changing and list changing, both of which have perfectly good buttons in the main control area already so are just duplications of exiting functionality.
I'd suggest up/down and left/right be selectable from a few options, including:
Volume control
Skip by user-selectable periods (e.g. to allow 10 seconds forward/backward for left/right swipes, and 60 seconds moves for up/down)
Track change (next/previous track)
List change (e.g. next/previous album or folder)
I'm sure there are other possibilities too, maybe a better (incremental-movement) timeline scrub feature?
Andre