Nintendo has yet to announce when its first smart device game featuring characters from its iconic franchises will be released, but speaking during a Q&A session following yesterday press briefing, Nintendo President Satorua Iwata said he hopes it'll be some time within 2015.
“Regarding the individual video game titles, when it will be launched, we will be making the announcement when each of those games are ready,” Iwata said (via IGN). “At least, however, we believe that there is no mean of collaboration [sic] if we can’t launch anything, at least once, or some sort of output within this year. Also, per game title, regarding the roles of each companies will differ depending on games."
As announced yesterday, Nintendo entered into a "business and capital alliance" with DeNA Co. to develop and operate games for smartphone devices starring characters from Nintendo IP. Games developed will be original for smart devices rather than ports of already released Wii U and 3DS games. Unfortunately, we don't know which Nintendo franchise will be the first to get a smartphone game.