PS4 achieved 14.29 million units of sales for the whole of 2014, that was with 1)Infamous Second Son, 2)Infamous First Light, 3)TLOU remastered, 4)Driveclub and 5)LBP3.
Also white PS4, multiplats, Destiny and Watch Dogs boost being major factors.
This year we have 1)The Order, 2)Bloodborne, 3)Until Dawn, 4)Tearaway Unfolded, 5)Ratchet & Clank, 6)Fat Princess Adventures and 7)Disgaea 5 for AAA, full retail releases and those are the retail exclusives.
Then there's 8)Drawn to Death, 9)Kill Strain, 10)Deep Down and 11) Let it Die for AAA free to play games, that anyone that owns a PS4 can play for free, those are all exclusive too.
Finally for the exclusives there's 12)WiLD, 13)Rime, 14)Everybody's Gone to the Rapture, 15)Alienation, 16)Shadow of the Beast and 17)The Tomorrow Children, indies that are exclusive to PS4.
So we have 2014 with 3 outright PS4 exclusives, there may have been some indies in there and 2 cross gen releases.
For 2015 PS4 has 17 outright exclusives that you can't buy or access on any other gaming platform, that we know about for now.
There's also God of War 3 remastered, games like Persona 5, Killing Floor 2, Orcs Must Die 2, The Witness, among others that aren't coming to Xbox or Wii, may be on PC or a Playstation platform, but will all be the definitive console versions of those games.
IMO a 50% increase in sales compared to 2014 is a low estimate of what's going to happen, based on the games we know about and the price staying where it's at right now.
Bundles will be available, Black Friday and XMas Sales deals will be all around, old games will be had for cheap prices too, that will all have a snowball effect on how PS4 sells this holiday.
IMO I think Guerrilla Games will have Horizon ready this year, it was rumored to be a Fall 2015 release before Uncharted started getting hinted for that, with the delay of U4 to Spring 2016 it leaves a huge whole for the Holidays, so Sony will have stuff to fill that.
Horizon's been in development for ages, over 4 and a half years by the September, I think it'll be a November 2015 release. Guerrilla has been releasing a game every 2 years since KZ2 came out, Killzone could do with a breather for another year.
Horizon would be a huge standout game, as big as Witcher 3 in scale, but an open world, western futuristic action RPG, with cool character design.
I think GT7 will be ready this year, there have been hints at that being the case.
There will be a price cut in the Fall, probably down to $349 because that's all Sony needs to do to stay on top.
Ratchet & Clank will IMO be a huge Fall release, it has a movie to tie-in to the marketing, kids will go mad for it and fans of the series will too, like me, I can't wait for that game.
There's tonnes of reasons for PS4 to hit top the 40 million mark by the end of 2015, even without GT7, Horizon and a price cut.
Batman and Metal Gear branded consoles, 17 outright platform exclusives that cover everything but the FPS, Fighting and Racing Genres, but all genres that work well for Playstation.
Free 2 Play games anyone can try for nothing.
PS Plus has been getting better and better, that can move units, it's a great value service.
I won't be shocked if the OP's predictions are right in the end, but I think Sony won't go so hard on the price cut, simply because it's not needed to have that level of effect on moving hardware, if they did then I think you could add a few million more to the end of 2015 total and if GT7, Horizon and something like The Last Guardian do come, along with a big Ratchet & Clank Fall push then sales will jump even higher.
