According to Polygamia, Microsoft was forced to revise their launch plan due to the big changes they have made to please the majority of gamers. Apparently, the console will be launching in only 13 countries compared to the original 21 announced.
The rest of the world will be getting the console sometime in early 2014. But please keep in mind that this is only a rumour, even if it sound very plausible.
The changes that Microsoft in currently making in the Xbox One could result in a delayed world-wide launch.