It was christmas, it was a new console and it had Mario, the biggest game on the console till now. I think that's about it.
Wiiu had a couple of spikes when big software was released (DQX and Pikmin) but that's about it. Right now it's a very bad product, almost no games the whole year and a big price to boot. Specially because one of the consoles aims is children and their parents don't want to pay such a high price. The gamepad is a viability too. The only games till now that uses it well are Nintendoland and Game and Wario and those were released a long time ago already. Only now Nintendo is releasing another game that uses it well, which is Wii Party U.
I think that's about it. Wiiu schedule for the holidays is a little better. Mario, Taiko, Mario and Sonic, Party U and the bundles might help. Even Disney Infinity might get a little bit of the pie considering the time it's released, but, to me, it all depend on those bundles. If they manage to get some of the Wii audience in, those games will do well. If not, the situation is preaty bleak.