I don't know about that. The DRM uproar was over how we are able to use games, purchased for a particular game system, on that system e.g. used games (which includes renting and loaning games). This is about a feature-- a current standard feature, absolutely-- of media playback that is peripheral, not a part of the core functionality of that machine, as I understand the PS4 to be a games console. Sony isn't making any statement as to your ownership over mp3s, just that you can't play them on their new console at launch. Clearly to those of you that have been using your PS3s as your main media hub via DLNA or whatever are going to be the hardest hit with this decision, as well as those who played custom soundtracks with their games. Both totally legit uses that I personally never got into but that's not the point. I'm definitely in the camp that thinks the feature ought to have been left in; DLNA at least.
As I said, I'm surprised Sony went that route and it'll be interesting if the initial meltdowns here and elsewhere translate into anything concrete for them down the road in terms of negative financial impact. The system hasn't launched yet so I have no idea, tbh.