This isn't surprising, but the headline isn't totally correct.
Sony and MS both said they will support used games. However, they haven't released the "how". That's because both of these systems will likely have to activate your games to your account, and it will become a part of your digital games library. Once you have that system in place, it becomes a bit more complicated for Sony or MS to make selling used games as easy as it is today. However, the benefits of such a system is that you don't need to swap discs anymore, and you can just download any game onto any Xbox where you're logged in. You also aren't screwed if you either break or lose your discs. The only times I've bought a used game this gen is when I've broken or lost the discs, especially multi-disk games like LA Noire. I even remember how pissed I was when I got a scratch on the third disc for FF7 on the original Playstation.
It sounds like for the One that the processing of selling a used game will be the same as it is today. You just take the game to GameStop and you're good to go. The process will be different for the Gamestop employees as they now have to scan a code to deactivate it, but as consumers we shouldn't care about that.
However, there are details on how you can do private party selling, and they haven't given the details about that. For all we know, it's done purely through the software now. What if they have a system like Amazon has for the Kindle where you can lend your friend a game digitally through XBL, or you can sell it digitally in some marketplace. These are the details that we do not know.