During an investor's meeting at E3, Nintendo president Satoru Iwata confirmed a free-to-play title is on the way.
Noting how this upcoming project wouldn't be a Super Mario Bros. or Pokémon title due to players having a good relationship with these established brands, the Nintendo president confirmed that the first free-to-play game would be available by the end of the current fiscal year (March 2014).
A free-to-play title would be as it says on the tin, free to download with the option to expand on the base content with paid packs/add-ons.
It wasn't certain which platform (3DS or Wii U) the project would be available on, but the likely candidate is Nintendo's home console.
What franchise (or new IP) could Nintendo use with free-to-play?