Tbh the big mistake they made with the Wii U was releasing it before they even had interesting games to launch it with. Although they kinda did the same thing with the 3DS and it worked when pokémon X/Y were released, but idk if Mario Kart 8 and Super Smash Bros will do it for them...
Whatever, I have the Wii U, and I can't wait for the next Mario party <3
The only thing that's relevant for the Wii u for the next few years is sadly a kart racer and brawl.. the majority of us grown men don't play Mario when we "kickit" bye.