I don't really think this generation will be 8 years like the last.. My guess is closer to 5 years. I do NOT think any of the consoles will hit 100 million in 5 years.
Generation 8 Totals:
PS4: 85-95m
X1: 65-75m
WiiU: 40-50m
So.. I don't think we will see the PS4 matching Wii totals.
XBLive: cpg716 PSN ID: cpg716 Steam: Luv4Tech77
Predictions on 12/01/15 - Generation 8 Totals:
PS4: 85-95m
X1: 55-65m
WiiU: 20-30m