The PS4 is passing the PSP, 360, GBA and PS3 as we speak

[JRPGfan]

~4,5 years into it:

PS1 = 58.19 million
PS2 = 73.46 million
PS4 = 82.20 million

*numbers by KillerMan91 from Resetera.

PS4 is doing pretty damn well, and by next year, it ll probably be above the Wii (launch aligned).