Hardly makes news, but I thought I would mention it.
Yes, Steam have released an open beta for their in-app music player that can be accessed from the in-game overlay (the one you get when you press shift + tab).
IMHO this is pretty pointless for PC users who can easily have their standard media player – i.e. Spotify, iTunes etc. – running in the background and map some key bindings to it to control it without having to Alt+tab out of a game. If you don’t know how to do this by the way, check out Auto Hot Keys with a little patience you can map literally any command to a key binding. I will add my script for in another post.
However, if you are using Steam’s Big Picture mode, this might be useful; and with Steam OS on the horizon it’s understandable why Steam might want their own version of a media player. On the contrary, I am a developer and I therefore will always stand by the phrase, “Don’t reinvent the wheel”