A week ago we reported about a leaked feature list of an Xbox 360 Spring Dashboard Update. Xbox Live General Manager Marc Whitten says in an interview with Next-Gen that there is no Xbox Spring Update planned this year.

So obviously the leaked feature list is a fake or refers to a future Xbox Dashboard update.
Marc Whitten announces though a new DRM management and to delist underperforming XBLA titles.

The rumored Xbox Spring Update feature list mentioned support for a motion sensor. It could be thought that Microsoft is considering a Fall update for the Xbox to make things exciting for the essential holiday shopping season.
More details on Next-Gen. Via Major Nelson.