I'm going to do a full review of Music Unlimted as it deserves to be appreciated. New ps4 owners get a 30 day trial and I suggest trying it.
Yes, Shu Yushida in an interview said mp3 support wasn't included at launch because their focus has been on games and making sure their focus was on that.
Over in the discless circler they're talking about Sony dedicated DSD players so I may add one as a companion device for hi rez file playback. But Music Unlimited is stellar on ps3, and my guess is Music Unlimted on Ps4 is an end-game solution for music playback. Streaming music has grown up and stands toe to toe with more traditional forms of playback.
But back on topic, for gaming, ps4 promises extremely high res, positional audio beyond what we've ever experienced previously. Can't wait to try it out tommorrow at midnight.