Hm. Sony's consoles take up the #1, #2, #3, and #5 top-selling home consoles of all time prior to the release of the Ps5. (I think we all know the Switch is gonna wiggle its way into that top 5 somehow; it's doing too well, too consistently to not.)
Put all of those consoles together and you get 461.29 million consoles. PS4 is still gonna get another few million, since Sony consoles regularly sell well for a year or more after their successors come out, and with Backwards Compatibility I can genuinely see the PS4 doing PS2 numbers post PS5 launch, since so many people might say "Get a Ps4 for now, get all the games, and when the Ps5 is cheap we can just transfer everything over". It's a bit of a stretch, but I think it's reasonable.
As of right now, the average is 115 million consoles between the PS1-4. I figure the Ps4 will end up about 124-132 million, and the PS5 will do about the same. so I'm comfortable saying 120 million. THAT SAID...I wouldn't be surprised if, given the shift in momentum this last generation and the fact that Sony is just cruisin' on a wave of good press and good decisions that started with the PS4 and haven't really let up, I wouldn't be surprised if it got as high as 140-150 million. They're doing pretty much everything right as far as I can tell, from the focus on fast loading and versatility to the balance between cross-gen and next gen games to the new controller and pretty much everything else. Plus, rather than take 2-3 years to build up steam with their library like they did with PS3 and 4, they're coming out the gate with an absolutely stellar first year with a bunch of games that are either sequels to mega-selling, critically acclaimed hits, or remakes to classics that were overlooked in their time, or a few new IPs that genuinely look great so far (But could be duds; we won't know till they're out.)
Point is, I don't think we're getting a PS3 flounder this time. They learned their lesson, applied those lessons to the Ps4, and it paid off heavily. It looks like they're continuing that momentum with good decisions and great games that appeal to a wide variety of worldwide gamers. My official guess is 120-130, but it appears I got overzealous and already voted 140-150 (No big deal, I could see it in either range depending on how things shake up.
My Console Library:
PS5, Switch, XSX
PS4, PS3, PS2, PS1, WiiU, Wii, GCN, N64 SNES, XBO, 360
3DS, DS, GBA, Vita, PSP, Android