no... seriously, even if wii u would be the most successful console i just don't see any console coming close to 240m. there is just too much competition so that a single device won't reach those numbers. not only will sony, microsoft and nintendo battle each other a lot, there will be also an in my opinion very healthy pc gaming market next gen so that at least some hardcore players won't buy a console anymore because ps4 and xb1 are so close to a pc this time that pc should also get most of the console games and the few exclusives the consoles will have will be compensated with pc exclusives. i would almost bet that the pc gaming market isn't shrinking (like the pc market in general)
competition from maybe google, apple, amazon and stuff like that will take some sales of the mass market. maybe hardcore players won't buy devices from them but a lot of the casuals don't care about the specs and just as example the probably coming amazon "console" could be enough for many who only want to play some games from time to time.