I agree that handheld gaming, in general, has declined considerably so it might be possible that the 3DS sales stagnate at around 80m. The Wii U will do at the very least 40m (hopefully) so at 120m, it would be pretty difficult for the PS4 to beat that.
I don't agree that the 3DS will outsell the PS4 as some users have suggested. I say this because of the decline in the handheld market and the fact that there has been no evidence to suggest that console gaming will/has declined.








