this would be a good move for Nintendo, demos for the mobile sphere, and save your real games for your devices.
If Nintendo steps into the mobile gaming market they will waste a lot of energy trying to compete in a whole new area of gaming. they will be developing new software or porting old software to two new platforms (android and iOS), that are fragmented over different types of hardware, and competing with developers who have been there for many years already.
Go play Super Mario 3D world and then tell me you can replicate that on a phone. I'm sorry but you can't.
Nintendo's place is in the living room or a mobile device of their design, not your smartphone.
The next Smash Bros,. and Zelda, and Mario Kart, and other 1st party titles will be a shot in the arm for Wii U sales, the console will likely go the route of the Gamecube, which was not a success but was still profitable by the end of it's run.
Nintendo's next move should be as the recent rumors have pointed to; a console/handheld fusion device with backwards compatibility to Wii and Wii U, support from Nintendo's online market, and specs at least somewhere in the ballpark of the current offerings from Microsoft and Sony.
A seamless mobile and living room gaming experience.
Did mac clones help Apple? No.
Then why would Nintendo commit suicide just so you can play Mario on your iPhone?
Aside from top notch game making and an earned reputation for making some of the best games in the business, the most valuable thing Nintendo has is its catalog of retro games and its intellectual properties.
Putting those games and/or properties on other devices is like throwing money away for Nintendo.
When you buy a game on Nintendo's virtual console they earn 100 percent of the profit, if they were bleeding them off onto other devices they would be earning less than if they sold it themselves.