Far from a confirmed feature, but still a positive prospect, comments made by a Microsoft developer at the company's recent BUILD conference in San Fransisco reportedly confirm that getting Xbox 360 games running on its new Xbox One console is being considered (
via Kotaku):
During a session by partner development lead Frank Savage on the Xbox One’s use of Windows technology at Microsoft’s Build developer conference, the issue came up during audience questions. Here’s the exchange in full:
AUDIENCE MEMBER: Are there plans for an Xbox 360 emulator on Xbox One?
SAVAGE: There are, but we’re not done thinking them through yet, unfortunately. It turns out to be hard to emulate the PowerPC stuff on the X86 stuff. So there’s nothing to announce, but I would love to see it myself.
Microsoft isn't a stranger to official emulation, as several games from the original X86 Xbox were configured to run on the Xbox 360's PPC processor in a limited initiative referred to as 'Xbox Originals'.