That's true. I wonder how consumers are going to respond. From a consumer perspective, there's 2 sides to a trade-in: the person who trades a game and the person who (potentially) buys that traded game. Not being able to trade a game in towards another game greatly affects some people's ability to buy new games. On top of that, what happens when someone buys a game they don't like or one that just sucks? The only recourse was to trade it in and get back as much as possible. So much for that.
And so much for lending a friend your copy. So, yeah, 3rd parties might love this, but it totally sucks for consumers and they're the ones buying the games. I'm curious to see how this would play out. I typically buy my games new and do not normally trade games in, but I like having the option to trade in games and buy trade ins.