Christmas time will be the deciding factor. With monthly updates, unannounced games, Possible GTA V GOTY port W/ new DLCs, Forza Horizon 2, Sunset Overdrive, Quantum Break and a Halo game slated for the 2nd half of 2014, 26 more countries for the holiday boost and Black Friday deals, I can see Xbox One having a 1 million unit selling week. I don't see Bayonetta, X or Hyrule Warriors being system sellers for Wii U and SSB hype will be sedated by the early 3DS version so people will have already had their fix. So X1 could definitely win the Holidays which in the end will win 2014 for them.

No, because Nintendo is blowing its big guns this year with MK and Smash.

I won't be surprised if it does pass though, either. It's going to be fairly close either way.

In the long term though, the Wii U loses no matter what. It's a colossal failure and deserves everything it gets.

Xbox One will pass the Wii U by the end of 2014 or early 2015. Not really a question of if, just when.

I'm assuming this was directed at me even though you didn't quote me. 

I don't think Nintendo is just going to give up on pushing the Wii U. (They haven't really pushed it at all yet...) This Holiday will be big for them I imagine. We will know for sure coming E3. 

I feel like people are generally underestimating the Nintendo Christmas Effect as seems to happen every year - even the dead-Wii managed to pull off respectable sales during that period; the WiiU will do very well since it will also have games to sell itself.

Somewhat, wouldn't be too surprised if they were about equal though.

For me no.
Prevision for th end of year:
Wii U: 12-13 milion
XO: 8-9 milion

No, I won't be surprised, because if the Xbox One does pass the Wii U it won't be too far ahead starting 2015.  I'm thinking the Xbox One either doesn't pass it, or barely passes.

Where was this last year???

It's a myth, it didn't happen before Wii and it hasn't happened after. It was just the Wii and DS selling well.

Heck even 3DS doesn't have the 'holiday effect' (it's novembers in the US are always weak) it just has the benefit of selling equally well in all three big regions.

No I wouldn't be