Yeah, I'll admit to being wrong. I really thought that November 2012 was a good bet. I'd say that November 2013 is the most likely release, but honestly, I'm not sure.
The biggest indicator that a new console isn't coming, is the price of the current console. I'm absolutely amazed that the Xbox can still sell console packages for $299.99 (Sure, it may come with Kinect and a bigger HDD or whatever, but still). 300 bucks is quite a bit of money, and people are still paying it. When that Kinect bundle is selling for $199, and a core 360 is selling for $149.99, then I think the next Xbox would be on the horizon, until then, nada.