The gap between the launch of Microsoft's original Xbox and the debut of its successor was almost exactly four years. The gap between the company's second and third console launches could end up twice as long.
Develop reports (http://www.develop-online.net/news/38917/Sources-point-to-2013-launch-for-Xbox-Next) that chip manufacturers and software middleware firms expect the next Xbox to be announced at E3 2013, with a launch following in time for the holidays. This would be an announcement-to-launch timeline similar to the Xbox 360, which was revealed just six months before the console hit retail in November 2005 (http://www.gamespot.com/news/6123821/mtv-xbox-360-coming-in-november).
The report also suggests that Lionhead is already at work on "Fable Next" for the forthcoming console. Various other development houses, including EA and Crytek, have also been rumored to have preliminary development hardware.
These reports follow a recent confirmation that various Microsoft employees are already on the next console team. Several LinkedIn accounts for Microsoft employees listed them as working on the hardware, with Jeff Faulkner pinpointed as creative director on "Xbox Next Gen."
Source: Gamespot.com (http://www.gamespot.com/news/6341339/next-xbox-to-launch-in-2013-report)
I'm glad to see that Microsoft is not rushing out their next-gen console. A big part of that is mostly due to strong sales this generation, but I still thinks there's plenty of life left in these current consoles.