Congrats to Switch. At this pace they can possibly hope to sell 20m hardware next year which is looking really good for the console. I've underestimated Switch again unfortunately this year. Thought it would end at 25m but of course they should already pass that mark after the next week (Black Friday).

PS4 and Xbox One on the other hand really look like they are on their way out this year. With these two consoles, I've overestimated them both. Especially
PS4 because I thought that they both will have it's peak year this year. How wrong I was. PS4 is already down 2m YoY which I can potentially see ending up in 3-3.5m drop by the year's end. For Xbox One though, things looked pretty nice until last week which was Xbox One X launch week a year ago. But yeah, this drop is huge. They lost almost 1m compared to last year in two weeks and I suppose it will only get worse in the following weeks especially considering their bad Black Friday deals and the fact that MS chose wrong games to market their console this holiday - the games with such a critical backlash as Fallout 76 and BFV. I expect XB1 to finish below 7m this year which definitely is not a good sign.

So, if I were to guess years's end sales now I think I would go with:
PS4 - 91-92m
XB1 - 42-43m
Switch - 28-29m