There is the age old issue of "selling the pelt before the bear is shot" as we say here.
Don't get too ahead of yourselves, it's been one week and nothing is decided, a fantastic holiday doesn't equal awesome year-round sales by default.
And, let's not count the One out, it will probably take most of the UK and US market and Japan is fast becoming too irrelevant to tip the scales in a big way globally for home consoles.
As for the Wii U; it's not entirely out of the match but it certainly is in round 11 and getting jabbed pretty badly for now.