Just two years into the life of the Wii U, Nintendo has revealed it's already working on a successor.
Here is a quote from Satoru Iwata
As proof that Nintendo maintains strong enthusiasm for the dedicated game system business, let me confirm that Nintendo is currently developing a dedicated game platform with a brand-new concept under the development codename "NX". It is too early to elaborate on the details of this project, but we hope to share more information with you next year.