An unconfirmed list of purported Xbox 360 Spring Update features surfaced on Tuesday night, lending further credibility to rumors that Microsoft will release a Wii-like motion controller for Xbox 360.

The list of features, obtained by Kotaku from a tipster claiming to be close to an Xbox insider, includes "options for motion sensor devices" and the ability to "store installation data on Storage Device for faster loading" among other things.

In response, a Microsoft official told Joystiq on Wednesday: "We don't comment on rumors or speculation, but what we can tell you is we've never seen this list before."

Rumors of an Xbox 360 motion controller surfaced in late 2007, something Microsoft didn't outright deny.

In April, an anonymous developer told MTV News that Microsoft was hastily planning to launch a Wii-like controller later this year, in an effort to compete with the raging success of the Nintendo Wii. Ambiguous comments from both Microsoft and third-party tech companies since then have done little to clarify the reports.

Microsoft is currently the only console maker not supporting some kind of motion-sensing controls. The Wii uses them as primary input, while the PS3 supports secondary gesture-based controls.