Soundwave on 03 December 2015
I have my doubts. Nintendo has said things like this before.
Fact is, they didn't really show any true new Wii U games at the November Direct, and they always show new software during that late year Direct. So they keep saying this, but they show no games to back it up. They showed nothing new at E3 either other than Amiibo Festival and Mario Tennis, both of which are fairly dubious releases. So if that's their idea of "software support" (outsourced low quality projects) ... they can keep it.
Also if NX is late 2017, then it better be able to compete with the Playstation 5 (FIVE) not the PS4, otherwise they will get Wii U-ed again. Releasing you own PS4 level machine 4 years late is a disaster waiting to happen.
