Pues la teorìa se ha confirmado. La venta de juegos de segunda mano se hará via digital mediante un supuesto Mercadillo. 
Asi lo ha confirmado Phil Harrison para Kotaku. 
El usuario podrá vender su juego (licencia) via online al precio que él indique. Tú pierdes la licencia a cambio de dinero. 
Xbox One games will require a one-time activation code to use, but you'll still be able to trade and sell them online, Microsoft tells Kotaku—although we're not 100% clear on the details. 
Speaking to us at the big event in Redmond today, Microsoft corporate vice president Phil Harrison clarified a couple of details about the system's used game policy and explained that there will be a solution for people who want to trade games with their friends. 
Here's how the system works: when you buy an Xbox One game, you'll get a unique code that you enter when you install that game. You'll have to connect to the Internet in order to authorize that code, and the code can only be used once. Once you use it, that game will then be linked to your Xbox Live account. "It sits on your harddrive and you have permission to play that game as long as you’d like," Harrison said. 
Other users on the console will be able to play that game as well, Harrison said. So you don't need to buy multiple games per family. "With the built-in parental controls of the system it is shared amog the users of the device," he said. 
But what if you want to bring a game disc to a friend's house and play there? You'll have to pay a fee—and not just some sort of activation fee, but the actual price of that game—in order to use a game's code on a friend's account. Think of it like a new game, Harrison said. 
"The bits that are on that disc, you can give it to your friend and they can install it on an Xbox One," he said. "They would then have to purchase the right to play that game through Xbox Live." 
"They would be paying the same price we paid, or less?" we asked. 
"Let’s assume it’s a new game, so the answer is yes, it will be the same price," Harrison said. 
But that doesn't mean used games are dead. In fact, Harrison told us, you'll be able to sell your Xbox One games online. 
"We will have a solution—we’re not talking about it today—for you to be able to trade your previously-played games online," Harrison said.
The Xbox exec wouldn't give further details on how this system will work, but we're assuming that once you're done with a game, you can trade the code online and it will be erased from your machine. But what will you get? Other games? Microsoft Points? 
No matter how the final system works, it is not likely to please GameStop, the world's biggest buyer and seller of used video games, but it could be a tantalizing way to share games with your friends in the virtual space. 
http://kotaku.com/you-will-be-able-to-t ... -509140825MERCADILLO XBOX LIVE Major Nelson dice que la Xbox One está diseñada para que el usuario pueda vender y usar juegos de segunda mano. 
We know there is some confusion around used games on Xbox One and wanted to provide a bit of clarification on exactly what we’ve confirmed today. While there have been many potential scenarios discussed, today we have only confirmed that we designed Xbox One to enable our customers to trade in and resell games at retail. 
Beyond that, we have not confirmed any specific scenarios.
Esto no tiene mucho sentido si fuera un método tradicional. Una consola ACTUALMENTE no te permite vender tus juegos, pero parece que la nueva Xbox One si.
Lo peor es que Microsoft se llevará comisión de la operación (como no), y el juego de segunda mano te puede valer lo mismo que uno de la estanteria de la tienda.