Yeah, i think 3DS has seen it`s peak year.
Smash might boost 3DS sales, but it won`t go as high as they could go because there`s a Wii U version coming aswell. That will cut into it`s sales for sure.
I think it`s time for Nintendo to really invest in a 3rd pillar: mobile market.
Not to bring games to Apple or Samsung, but actually invest in it`s own device and port VC games aswell as have dedicated games made specifically for that device (with the option to also download them on other Nintendo HW).
If it can`t do that alone, partner with someone like Samsung.
More and more those mobile devices will offer better experiences and at cheaper prices aswell and Nintendo will lose more and more ground on one of it`s most important markets: kids.
That would be the best way to bring Nintendo franchises to those kids and dads who will only buy tablets and smartphones.
