PS4 has a shortage currently.
It's clear that they are discontinuing the OPS4.
Clear out the stock and release a new model.
As for Vita, It needs a new type of game that will revitalize it. This niche games has done it's part already
or a price cut (afaik there's isn't one yet).
For 3DS. it will sell again when Pokemon Sun and Moon is out and I think it will be the last push for the system
For Hatsune Miku. It's a bomb alright.
Nice 2nd week and hold for Tales.