Today new update was released on Xbox One Preview Program. Currently all preview members is testing new March update which is coming sometime this month for Public. This new update will have lots of new features!
One of the biggest additions to this update is the ability to purchase Xbox 360 games that have been enabled for backward compatibility with Xbox One in the Xbox One game store. Previously, players who wanted to buy an Xbox 360 game that worked with Xbox One had to do so either on the Xbox 360 itself or through a web browser. Now, a separate section of the Xbox One still will display, showing Xbox 360 games that are able to be run on Xbox One.
This is NOT the final update! More updates to come :)

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