It was rumored that Sony came to the decision to oppose DRM-laden policies very late in the game in response to Microsoft, but that's not so, according to Sony.
At a Sony Roundtable today, President of Sony's Worldwide Studios Shuhei Yoshida stated the following in regards to used games: "We didn't make a policy decision [for other company's mishaps] -- it takes time and effort. We are going to treat disc games like the PS3 because there are a lot of people that like to share their games…we do expect more people will gradually shift to all digital, but it's not going to happen overnight. There are still parts of the world that do not have robust internet infrastructure.. but it's important to provide what people need."
In other words, things will continue as normal on the PS4 -- no strict anti-consumer check-ups, and no restrictions on used games. Yep, I can see this working out very well for everyone involved. Nice job sticking to your guns early, Sony.