I think it will be out sooner than that and signs are pointing to this already.
Iwata said it would take two years for them to come up with the redefined (unifed/iPhone-iPad like ecosystem) platform that he was talking about, that was in spring 2014.
AMD who is rumored to have scored a portable console contract (sounds an awful lot like Nintendo) are saying that chip will be for a product releasing in 2016.
Even the custom shaped LCD tech from Sharp (I think) is targetted for a 2016 launch.
3DS has an OK 2015 lineup, but it's definitely running out of gas. Summer-fall 2016 is my guess.
For people who say it's too close to the New 3DS, the DSi XL launched just one year before the 3DS. New 3DS if anything smells a lot like the typical Nintendo "last gasp" revision before rolling out their successor (see also: DSi XL).







