Some interesting choices. The omission of MP3 playback and DLNA client seems a strange one. The only logical reason I can think of why this is, is so they focused on the gamer first aspects of the PS4 and getting those features built into the system at launch, with the media side of things coming later. PS3 never launched with DLNA, and although MP3 does seem basic, having dropped CD playback and therefore CD ripping, I can see MP3 playback as taking a back seat. It also has the benefit (for Sony) of some Music Unlimited advertising in the mean time.
I would think that most of these issues get resolved within the first year. I would guess that, in their minds, launch consumers are more interested in the latest hardware to play games on, rather than media streaming or mp3 playback. For example, I am far more interested in remote play capability than MP3 playback at this stage. And more than likely, those first day buyers have a multitude of devices that already have those features. As in TV's, Home Theatre, DVD/BD players etc. It would have to be at least 4 or 5 years since the majority of TV's didn't feature DLNA or MP3 playback.
Not that I'm saying it's ok, I would rather the PS4 have those features, or at least confirmed as an update down the road. I'm just trying to think of reasons why they would omit such features on a box which integrates into your home entertainment so neatly.
On the bright side of things, I found this tidbit interesting...
Is it possible to output all game audio through DUALSHOCK 4 controller’s 3.5mm headset jack?
Yes, you can select the Output to Headsets option to either ‘Chat Audio’ or “All Audio.”
I think that is very cool.