This is an interesting story that has shown up today.
Spotted by user duckroll over on Neogaf, Nikkel has posted an article claiming than an insider source has informed them that the OS for the Nintendo NX will be Android based. After support was dropped by third parties for the WiiU, Nintendo will be taking a different approach and using a more open platform with Android to give developers the freedom and flexibility to create content for the NX.
This is purely speculation at the moment, but Nikkel has provided information on Nintendo before that has turned out to be true so it’s interesting at least. It also add some fire to the rumour that the NX could be Nintendo’s take on a smartphone. Nintendo has said they won’t be talking about the NX at E3 so it’ll be a longer wait before we hear anything official.