For reference I am going to use this webpage:
Of course I am not going to copy it all here, but it comes down to the fact that they want to implement chips on cd,s so that if you put it in your PS3 (or 4 in the future) it recognizes it. Then if you put it in another PS3(or 4) it will not work.
Now I don't think they will do this yet, and they have not done it yet.
But it would be a real bitchslap against consumers because reselling games and/or lending a friend a game would be dead.