According to a source that spoke to Gamereactor, Microsoft may be delaying the Xbox One till the first quarter of 2014. However, it seems that a January or February release is unlikely, so the console could be set to appear in March if such a delay actually happens.
There is no confirmation on whether this is limited to Europe or pertains to the worldwide launch of the console, and for that matter, no reason has been given for the delay. Could it be tough competition from Sony’s PlayStation 4? A manufacturing delay? A shortage of units to meet targets? Your guess is as good as ours.
However, it’s highly unlikely that the Xbox One could release next year due to Call of Duty: Ghosts coming out in the same month as the console. The series has always been favourable for Microsoft’s consoles, and if rumours of Ghosts launching alongside the console are true, it could provide a major impetus for moving Xbox One units. So take this as a rumour for now.