Any kind of marketing helps Wii U.
But yeah, this is mostly related to Mario Kart 8. I remember for about 3 weeks leading up to the release of Pikmin 3, the console saw bumps. Yet, apparently, Nintendo doesn't value the benefit of consistent marketing, and keeping the awareness level high(this is especially true since they're a bit more weary of loosing too much $$ these days). They allow the Wii U to be forgotten for a couple months at a time. Then for a brief moment only, they remind the public that the console exists, when a game is finally ready for launch - which doesn't occur frequently enough, unfortunately. They've kept this weak stance since the console debuted, even though there's finally enough to shout about now.
Let's hope they keep their word and promote Mario Kart/Wii U throughout the rest of the year.
