It will do ok, but I think Sony has the edge in this launch in everywhere but America. But SOME OF THE CONSUMERS of America will buy the One outta of blind loyalty to MS and american brands, not because they sat and thought about it (like I did).
It will probably be like this (updated prediction with base on the 3:2 preorders at Amazon, which favors PS4):
XBOX ONE: 50%
(15 million consoles sold in the first year overall)
XBOX ONE: 35%
(20 million consoles sold in the first year overall)
Xbox One: 2% (Imports).
(6 million consoles sold in the first year overall)
Brazil and latin America (mostlly Brazil):
XBOX ONE: 47%
WiiU: 3% (Imports).
* Brasil numbers will be around 2 million consoles overall for the first year of the whole next gen.