I think its unfair to put all the pressure on Mario Kart/Smash Bros. That to me kinda implies that Nintendo could cancel every other upcoming Wii U game and literally just release these 2 games and Wii U will sell better. Thats dumb because most people buy a console for its library not just 1-2 games.
Its like if 360 only had GTA and COD, it would probably sell like shit. 360 sold well because it had a great overall library like Halo/Gears/Fable/Forza/GTA/COD/Ass Creed/Battlefield/Red Dead/Left 4 Dead/Elder Scrolls/Fallout/FIFA/Madden/Need for Speed/Batman/Splinter Cell/Force Unleashed/Far Cry/Mass Effect/Dragon Age/Saints Row/Ghost Recon/Kinect games/Guitar Hero/Rock Band and many more that im missing.
The way that Wii U is going to be saved(whatever that means) is get the manufacturing costs down so they can profit off it, continue releasing popular games and advertise them. Thats it, it doesnt matter how many units Wii U sells as long as they start selling it at a profit and its first party software has shown to be able to sell well even on a low install base. Take Gamecube for example, it sold just over 20 million and it still had strong first party software sales.
3D Mario, Smash Bros, Mario Kart each sold well over 5 million.
Zelda, Luigi's Mansion and Animal Crossing each sold 3-5 million
Metroid, Mario Party, Paper Mario all sold over 2 million
Pikmin, Star Fox Adventures/Assault, Kirby Air Ride, Donkey Konga/Jungle Beat, various Mario Sports games all sold over 1 million.
So basically Nintendos biggest challenge right now is getting the manufacturing costs down so they can sell it at a profit because the first party software will sell well regardless and we are already seeing that on Wii U with games like NSMBU, Luigi U, Wind Waker HD, Nintendo Land, Wii Party U, Pikmin all selling well on a 5.5 million install base.
When the herd loses its way, the shepard must kill the bull that leads them astray.












