There have been rumors of MP3 playback support coming to the PS4 with a future update, and something found by one of our readers that snooped on Sony Computer Entertainment Worldwide Studios President Shuhei Yoshida's PSN profile definitely seems to add solidity to those rumors:

Apparently Yoshida-san ran a "Music Player Demo" app yesterday, and it left very visible tracks on his PSN profile, as you can see in the pictures at the bottom of the post:

Of course we don't have clear information on what the "Music Player" entails, or if it'll really play MP3 files, but now we know that it exists, and it's being tested internally at Sony Computer Entertainment.

It's worth mentioning that normally this kind of unannounced app is kept hidden from profiles, but apparently someone forgot to flip that switch.

We'll have to stand by and see if the app will be announced any time soon, or if it'll make it in the upcoming 1.7 firmware update.

Update: commenter Carla Birch that has Yoshida-san on her friend list, provided another picture that labels the music player as "Bungie internal beta", as you can see in the screenshot and video she provided at the bottom of the post. That's interesting on multiple levels.

It's doubtful that Bungie might be developing a music player (but who knows, at this stage?), so it's possible that an internal beta of Destiny could be causing some kind of glitch and the Music Player Demo to show on the profile. This also tells us that Bungie is possibly running a private beta at the moment, and the news teased for Monday by the studio could be related to an upcoming public test in addition to the fall of a press embargo on a recent preview event.

Update 2: looks like the app, whatever it is, might have a social aspect to it as well.

//www.youtube.com/embed/Y-374E3v5po

[Thanks for the tip: Durandal, Carla Birch]