What makes comparison with the Gamecube or Xbox a fair comparison?
Both released after other consoles in their generation, both released as more powerful systems than the others within their generations, they launched simultaneously (meaning that they weren't the only new hardware), and both followed traditional controls. Both also had significantly staggered releases across the regions, allowing more ability to focus on a single region at a time. And neither one was next generation system for a highly successful console.
In short, there is no significant similarity between the systems and the Wii U to base the comparison on. It is simply a nonsensical comparison, and not at all fair.
Now, it might be a little fairer to compare with the Xbox 360, as at least it's the first system out of the gate for its generation, was the only one released at the time, and release wasn't significantly staggered amongst the biggest regions (NA, Europe, Japan). This at least provides some similarity to form a suitable base for a fair comparison.
So let's start with NPD figures for 2005.
November: 326k
December: 281k
Total: 607k
Wii U total: 885k
To emphasise why it's important to consider how far into the generation it is, here's the 2000 sales figures for PS2 according to NPD:
October: 391,245
November: 187,554
December: 522,239
Total: 1.1 million
Note that this is smaller than both Gamecube and Xbox, despite the system being out for about 3 weeks longer for its respective comparison. Also note that both the GC and Xbox had stronger December sales than the PS2.
By the way, for those who point to how strongly the PS3 and 360 sold in 2012's holiday period compared with the Wii U, I thought I'd demonstrate another point, since the data is right in front of me as I write this.
December 2005 numbers according to NPD:
Xbox: 415,000
Gamecube: 606,423
Xbox 360: 281,441
Notice how the new system, the 360, struggled against even the Gamecube? I left off the PS2 only because it was expected to sell huge given the strength of its sales in general - it's around 1.5 million for the same month.
The point is, the first system of a generation will generally do worse at launch than the others, because many people will want to wait to see the other systems before making their decision. It will also do worse than the systems of the previous generation, because those are well-established, significantly cheaper, and have a huge library of games - they will usually also have rather generous bundles for that particular holiday season, to help them to compete against the new system (this is likely why the Gamecube so significantly outsold the Xbox in December 2005 - the Xbox wouldn't have been given bundles, etc, to compete against the 360).