To make a succinct point:
The Wii U will not have the highest lifetime sales at the end of the 8th generation because Nintendo has not strategically planned out it's first party release schedule. In addition, third party support and major exclusives will not be heading to the Wii U.
Even if you examine the indie game scene, you would see a huge difference between the selection on Nintendo Network vs Xbox Live and PSN.
So let's break this down. First party support WILL NOT BOOST the Wii U into first place over the long run.