If 2014 doesn't win, Nintendo will really have to re-evaluate the Wii U's position in the market.
It should do well in 2014 as I think it'll get another price drop to "mass market" pricing. (Sub £199 in the UK) and Mario Kart 8 and Smash Bros will help to bring onboard the old faithful that haven't got around to migrating yet.
Mario Kart 8 could also be the game that convinces some Wii owners it's time to trade up.