PS4 Jan, Feb

Switch Mar, Apr

May-October is difficult. You never know what deals or bundles there may be. Nintendo might have something big up their sleeve for one of those months like Pokemon Stars

And November and December Xbox unless Sony cuts prices hard

Almost like it's out of stock.

Still number 3 on the monthly. 

Would not be surprised if the Switch and PS4 battle it out most of the month.  The Scorpio will do no favors for the Xbox One in the lead up to its launch.  It will be like the PS4 between the announcement and launch of the Pro only worse.  Though a lot of this will depend on E3, which is shaping up to be quite a battleground.

I wonder how many units they are planning on shipping for NA launch?

PS4 wins them ALL!!

I do think the PS4 is still going to win the majority of the months, especially if Sony cuts the price sooner than later.  Jan and Feb are theirs to lose.  March and April should definitely be Nintendo's.  If not, they are in big trouble. Then, up until Nov, I see Sony winning most of the months, as demand for a $299 ($360 with game) Switch begins to drop.

As for the last two, I don't really see the Scorpio being that much of a boost to the XBO's sales.  It's going to be as niche as the Pro, actually more so.  Especially if it launches for more than $399 and isn't quite the powerhouse MS is bragging it to be, i.e. a lot of games are using similar tech that Sony are using to get to 4K on more demanding games and still uses a Jaguar CPU.  It'll be even worse for the Scorpio if Sony decides to go aggressive and cut the Pro to $299.  That would be, at minimum, a $100 difference between the two, though it could end up bieng a $150-$200 difference.  The PS4 Slim is also going to be available for $199 at some point this year, either as a permenant cut or for Black Friday.  Couple that with its great lineup for this year and I doubt the XBO is going to take two months in a row.

Well, Reggie announced 2M WW.  My guess is they are going to be focusing more on NA and Japan, since Nintendo isn't doing so hot in EU and Others.  I'd guess ~800K-1M for NA, ~500K-600K for Japan, and ~400K-700K for EU and Others.  I doubt they have that many preorders, though.  Nintendo probably kept preorders low to create buzz since they sold out very quickly.  I'm sure they'll have a few for stores to sit on shelves at launch.

6 hours since last update:

HARDWARE
#13 PS4s UC4 Bundle (same)
#47 NES (down 1)
#49 PS4Pro (up 6)
#51 XB1s-500gb Battlefield Bundle (down 4)
#92 XB1s-500gb Minecraft Bundle (up 6)
#94 NiS (down 18)*

SOFTWARE (pre-orders only)**
#05 NiS Breath Of The Wild (down 1)
#14 Mario Kart Delux (down 2)
#81 PS4 Digimon World (re-entry)

PS4: 2 in the top 100 / 2 in the top 50 / 1 in the top 20 / 0 in the top 10 / 0 in the top 5
XB1: 2 in the top 100 / 0 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5
NiS:  1 in the top 100 / 0 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5

Does not affect this month: *
Software outside of the month only gets added if it's in the top 20: **

I think Sony will sporadically make the Pro and PSVR available, each time reassessing how many they need to make in order to meet the assessed demand. But as the Scorpio draws nearer, they'll push harder to increase productivity and have a regular stream of Pros sent out to retailers (not sure about PSVR yet).

How whas ps4 doing on amazon last year?
Ps4 remaining in the top 20 seems incredible for January.

Actually, I think that will depend on the demand they see.  If they see the Pro being a fairly niche product appealing only to those who really, really want the most premium experience and developers only use it for polish rather than substantial improvements, I image they will not bother to up the production much and just let the Scorpio run aground on the exact same rocks as the Pro.  Not to say the Pro isn't doing well enough to justify its existence and make money, but if it's going to be a fairly small subset of the PS4 installbase, the same will likely be the case for the Scorpio and if that's the case, Sony has little to be concerned with.

Sony doesn't  need to concern themselves  even if switch and scorpio will be a success. 

The ps4's lineup  is unbeatable. 

A60mill headstart is unbeatable (70 when scorpio launches)