Speaking of PS2, next week NSW will pass it launches aligned.
LTD week 144
PS2 Dec 2002
NSW December predictions
It should pass PS2 next week and by the end of the year have close to a 500k lead
This is a 1:1 comparison because they both launched in the first week of March.
So the PS2 sold like 23m in Japan and the 3DS 24.5m. If the Switch has a long life like the PS2 or 3DS did, then it will surely match them.