It sold 3.1 million units with no competition during 3 of the 4th quarter ( granted the 4th quarter is the biggest by far but still).
How can you expect it will do better in 2014 when it will have competition the whole year. I don't think even Nintendo execs believe that and they are always overly optimistics..

"Q1- 600K, Q2- 900K, Q3- 1.3M, Q4- 3.7M."

Hate to break it to you, but 6.5 million in sales is not good, or anywhere close. It would be decent considering where they're coming from, but it would still be exceedingly low. They probably need about 8 million to stay relevant in the generation, but 10 million to really turn the tides.

your quarter 3 sales are way too high.

It didn't have good games aside from New Super Mario Bros U and ZombiU back in 2012. It did have a bunch of gimped ports to spare though. More games = More sales.

I'm sticking to my 10m this year so yeah a pretty good year

Nintendo already said that Super Mario 3D World was not the main 3D Mario game for Wii U and I said Nintendo can have a better year if they announce any of these games for this year because although we have good games coming until Q3, there is not even one system seller coming in Q4, which is the quarter with best sales. Also, you can't say 3D World didn't help improve sales numbers because it did, but it is not a game to save Wii U alone. If there is a higher number of good games, more people will buy the console, and if more people have the console, these games will have better sales.

December has to be huge for them. Holiday bundles need to sell to families, so advertising must be much better than it currently is and the casual market must know that WiiU is a new console. I think a worldwide price drop will happen at some point this year, maybe to coincide with Smash. Otherwise not much Nintendo can do but push out games and advertise, at least they have nice games coming this year.
-Wii Fit U
-Donkey Kong Country: Tropical Freeze
-Bayonetta 2
-Hyrule Wariiors
-Super Smash Bros. for Wii U
-Yarn Yoshi
-X
-Project Cars
-Mario Kart 8
-Watch Dogs
-SMT X FE (Maybe)

Then theres the typical CoD, AC etc. if they are still ported to Wii U

There was plenty of competition from Xbox 360 and PS3 (and later other next-gen consoles and if you look at the entire over crowded consumer electronics market you will see that there is even more competition there), both of which had continious stream of game releases, better advertising, and lower price. I can see the Wii U doing better next year than it did this year though my estimates are fairly conservative about the system.

Relative to last year, it will almost certainly improve unless Nintendo completely screw up the advertising and put people off. However, I don't see how it can sell in numbers that would be considered "good" for a console in its second full year on the market, even with some top games coming out.