A report by CNET.com has indicated that the next generation Xbox console will be arriving in 2013, citing unnamed sources. It's far from an official confirmation, but as Brenna pointed out yesterday, a much better guess than 2012.
There's also word today that the design lead on the Xbox 720 project has been swapped. According to CNET, Don Coyner (the past lead) has been replaced by Emma Williams who was part of the team that just revamped the Xbox dashboard. She was officially "general manager of Xbox experiences."