Engadget reports that the fall update has just been made available to those in the preview program:
Shortly before Kinect hits store shelves on November 4th, Microsoft plans on rolling out the Fall Update to Xbox Live — even sooner for those who signed up for the preview program. That shouldn’t come as much of a surprise, really: even without the numerous leaks, the fall update is a longstanding tradition for the almost five-year-old console, and the company devoted a large chunk of its E3 2010 presentation to talk about the biggest additions. That includes Netflix search (finally!), Zune music, and an entertainment hub for a certain worldwide sports broadcaster… ESPN.
More details available in their News item. What you wonâ€™t find in there is that the new Xbox experience is finally Windows Live Messenger MPOP enabled. A source close to LiveSide just revealed this.