Nope. This generation don't will have legs. 2015 is the PS4 peack.
My prediction:
2013: 4,200,000 (4.2m)
2014: 14,300,000 (18.5m)
2015: 17,500,000 (36m)
2016: 16,800,000 (52.8m)
2017: 15,200,000 (68m)
2018: 13,000,000 (81m)
2019: 10,000,000 (91m)
2020: 5,000,000 (96m)
LT: little more than 100,000,000
For XBO i said:
2013: 3,000,000 (3m)
2014: 7,200,000 (10.2m)
2015: 7,600,000 (17.8m)
2016: 6,800,000 (24.6m)
2017: 4,800,000 (29.4m)
2018: 2,200,000 (31.6m)
LT: above 32,000,000