I think it will be a lot more to do with how the publishers want to sell their games, developing hardware like consoles costs a lot of money & they get this back via the games so publishers may ultimately force Sony, Nintendo & Microsofts hand.
Will people continue to pay £250+ for a console with old tech that will be superseded in a couple of years with the upgradability of PC's, i can see Sony maybe integrating the Playstation platform into blu-ray players or having a port on blu-ray players that you plug in a PS5 which contains a CPU & GPU, or maybe has a app that you buy so you just stream the games from a cloud.
I will change before the PS5 & Xbox1440, if the PS4 & X720 are out next year then there will be a six year wait until the PS5 & Xbox1440 would be released so that will be the year 2019 or 2020, just look how powerful the iPhone has got in the last five years & the games it can play, no i am not saying phones will take over but look how small they are compared to the power they pack.
Hmmm i dunno, he may have a point.
used to own - NES, Atari ST, Amiga 500, Mega Drive, SNK Neo Geo, SNES, Saturn, N64, PS2, GameCube, Alienware Aurora.
currently own - PS1, Xbox, Xbox360 + Kinect, Wii, PS3 + MOVE, 3DS, Games PC, Wii U.