Interpretation of a leaked Microsoft job post leads to conclusion that the Xbox 720 would be released in February 2014 at the earliest.
A job post leaked ( has been removed now) on Microsoft that had the following passage in it according to Slashgear: "Over the next eighteen months Microsoft will release new versions of all of our most significant products including Windows (Client, Server, Phone and Azure), Office and Xbox."
The internet immediately jumps to the conclusion that this means that the Xbox 720 comes in 18 months. I think this is very thin evidence to make that conclusion. I also do not see February 2014 as ideal for launch a new console. Microsoft will for sure chose a fall release date. In my mind the new Xbox comes Fall 2013.