No way in hell it will play ps1 or ps2 or ps3 games in the form of physical media. No chance in hell.... I do think they can offer them up on the network as they've been doing, though. the only way you're going to be able to play those games is by buying them digitally... That's just that. That or streaming them. Sony made a lot of strides and prep this gen by offering a lot of their games on the store digitally -- This wasn't just for the sake of doing it. It was done because that is the direction the Ps4 is going to take.
Be it the cloud or the psn store front or Gaikai... Games, Ps1, ps2, ps3 and psn will be delivered in one of those methods.
Sophistication is buying ALL of your games digitally, but it's more than that. It's a way of life. it's having the best games and telling the world about them