Things will be slow for the next few weeks, probably going sub 40k. Donkey Kong will give a nice boost for a few weeks then sales will go back down and hopefully Mario Kart releases sooner rather than later (late March/early April) which will for sure give Wii U a boost. Those 2 games alone should be enough to keep it up YoY for the first half of the year.
After that hopefully they can release Bayonetta 2, X, Hyrule Warriors, Yarn Yoshi, Sonic between May-Oct to give it a consistant stream of exclusives from late Spring-early fall. Smash Bros plus one other relatively big game for the holidays and a Mario Kart 8 bundle for $199 on black friday.
I think Wii U will sell over 5 million this year granted they space out there releases and dont have any multiple monthlong droughts.
When the herd loses its way, the shepard must kill the bull that leads them astray.