Depends heavily on supply. I think there is still pent up demand that PS4 and X1 will have strong Januarys with waiting lists starting to be worked on.

Demand, people want both next gen consoles significantly more than they wanted the wiiU. I don't know how to break it down anymore. If the supply is there, it's going to sell. 

I think XBO will win with 300k across NA and EU. 225k for NA, 75k for EU.

Only in America as far as the XBONE's concerned. In Europe the demand isn't there and in Japan the supply and demand aren't there. Even with amazing US sales it has to overcome the 215 thousand units the Wii U sold in other territories. That's far from impossible, but it's what makes my prediction realistic.

We'll know a lot more once the weekly sales come in tomorrow.

No, I think you're wrong.
Xbox One will do better than the WiiU in January. When the WiiU launched, most people didn't even realize it was a new console.

With more data in I'm feeling more confident in my prediction. World wide the XBONE beat the Wii U's aligned numbers for the first two weeks, but since then it is tracking worse. Not significantly worse but still the same ballpark.

In USA the numbers heavily favor XBONE, which is what I predicted.

Wii U did 67k in USA Jan so my XBONE range of 100-200k seems really accurate. Next week will be the most telling. I doubt XBONE will have as bad of a drop off.

In Europe the Wii U launched later so a week by week comparison isn't wise, but they are still very similar. Week ending 21/22 puts them at about 70k.

@OP
You keep mentioning Japan. But how many consoles would you think would be sold in Japan if the X1 were available with enough supply?

I kind of doubt it would make much of an impact on the overall sales.

XBONE is dead in Europe and things will be even worse in Japan. Doing ok in America just won't be enough to make up for the other regions. Japan is also not only a negative for XBONE, but a positive for Wii U. The system isn't going to beat the XBONE in America and is going to tie in Europe for the moment, but it'll certainly beat the XBONE in Japan. I keep mentioning Japan not because the XBONE isn't released there, but because it adds a wopping 150k to the Wii U's January sales.

A bit off topic but would you say that the X1 will sell better or worse than the 360 in Japan?

I'd say worse. 360 sales died off and I doubt many gamers are still fans of the brand.