Sony received a decent amount of backlash for the lack of MP3 playback support noted in their official PS4 FAQ (http://blog.us.playstation.com/2013/10/30/ps4-the-ultimate-faq-north-america/), also noting that background music during games would only be available via the Music Unlimited service.
Shuhei to the rescue!!!
Thanks for the feedback to the lack of MP3 and DLNA support at the launch of PS4. I'll share with the PS4 Dev team for future consideration.— Shuhei Yoshida (@yosp) October 30, 2013
Had a very good discussion w the PS4 Dev team today. We're happy & appreciative to learn so many people use and like PS3's media features.— Shuhei Yoshida (@yosp) October 31, 2013