So the PS4 sales seems to have plateaud last year, being only up 100k from 2015 despite 2 new SKUs. PS4 sold 17.5M units in 2016, up from 17.4M in 2015. Still impressive, considering Wii started its decline in the 3rd year.
I think 2017 could be PS4's peak year, there's potential with the amazing software line up, with multiple heavy hitters among them (RDR2, GTS, Destiny 2, BF2, FF7R:PI?).
The PS4 will see sub $199 price tags this year, I see $179 or even lower around Black Friday. The Pro should see $299. The cheaper price will see most benefits in other parts of the world where the impact will be bigger.
Sony will also be focusing a lot more on the US this year because the new Xbox marketing clearly affected them and put them down YoY.