After an article in Nikkei claimed Nintendo was to begin working on making games available for smartphones, Nintendo has come forward and clarified to Engadget:
Nikkei's article contains information previously stated by Mr Iwata during past press conferences, including statements which relate to Nintendo's willingness to make use of smart devices to promote our products.
However during such past announcements Mr Iwata has also stated that Nintendo's intention is not to make Nintendo software available on smart devices and as such, we can confirm that there are no plans to offer minigames on smartphone devices.
Don't worry, you didn't buy that 3DS for nothing.