The PS2 has sold very well.
The Wii has a chance of getting similar numbers, although I very much doubt it. I reckon they will get closer to half the numbers.
The DS though, has a very good chance of reaching the same numbers.
Prediction (June 12th 2017)
Permanent pricedrop for both PS4 Slim and PS4 Pro in October.
PS4 Slim $249 (October 2017)
PS4 Pro $349 (October 2017)