So Wii U is in a tough spot currently but it has alot of room for improvement, here is my breakdown for sales the rest of the year.
By the end of July Wii U will have about 3.5 million units sold (rounding to nearest .5m)
From Aug-Oct is has a some solid exclusives coming in Pikmin 3, Luigi U, W101, Wind Waker and Party U along with some advertising. I think those 3 months combined can push about 1 million units for a total of 4.5 million.
Nov/Dec has 3 big games that are most likely going to sell 5 million or more, those games are DKC Tropical Freeze, Wii Fit U and 3D World. Those games plus some decent holiday deals/bundles like Basic-$199, Deluxe w/extra game-$299 could push alot of units. Im gonna guess about 3 million pushing total sales to 7.5 million by the end of 2013.
When the herd loses its way, the shepard must kill the bull that leads them astray.