Soundwave on 03 February 2014
Depends on how you define "successor" because I think the next Nintendo portable will also be a hybrid/fusion console product with the 3DS existing alongside it for a few years.
That said right now I'd say
2014 - 12 million 3DS' sold
2015 - 10.5 million 3DS' sold
2016 - 9 million 3DS' sold
Seems like a reasonable assumption which brings Nintendo up to ... 73.5 million by the end of 2016. Looks like a no I guess.
