At this time good games are simply not enough to save Nintendo. A new Mario or Zelda with no voice acting , same story, no online play, and pretty much the same thing with better graphics and control scheme, is not enough to get people to into buying a Wii U.
Nintendo needs to completely re innovate their Mario and Zeldas, and make NEW game series. As I said before, better graphics and control scheme on next generation games are not enough to sell the same old series, even if it has good reviews. Just look at Super Mario 3D World.
Nintendo needs to put voice acting or make a whole new compelling story line in their Zeldas or Marios, or Make a MMO out of their games. They also need to make new a few new game series if they want to sell.
Why doesn't Nintendo re innovate their games, and instead just put better graphics? Why don't they make more games, outside of Mario, Donkey Kong, Zelda and Brawl?