Sony has a temporary price cut on PSVR and Pro but nothing on the scale of the $199 deals. I don't think the Switch will be affected too much by what PS4 or XB1 does anyway. 

$199 for PS4/XB1 definitely affected on Switch that's $300 in some degree, espacial because you had for instance some extra deals (Gamestop gave $50 in store credit). But most likly we want see that Black Friday deals during December so Switch will have very strong month.

Price cuts on the PS4/XB1 will affect the Switch but not that drastically. It's a cliché now but Nintendo consoles are a direct competition like between the PS and Xbox. That's why the Switch was able to sell nearly 900k with no deals and $100 more than the competition. 

When does npd for dec ends?

Switch is absolutely killing it in December.

December will be bigger for switch just due to it being a five week month as well. Ps4 and X1 will hopefully remain flat from November.

Amazon may not be a good gauge on who will win and by how much in general, but it still gives a good idea on if a console is still selling. Those periods where PS4 and Xbox shot ahead of Switch during November must have been by large amounts. If Switch can stay in those top two slots for nearly the entire December, then there is a good chance it win the month across the board.

8 hours since last update.

HARDWARE:
#03 NS Neon (same)
#08 NS Grey (same)
#19 PSVR GTS (down 1)
#21 PS4 Fool's Edition (down 1)
#25 PS4 Pro (same)
#40 XB1X (up 3)
#41 SNES Classic (up 1)
#44 N2DSXL T+B (up 3)
#46 PS4 Star Wars (up 2)
#88 XB1 Forza (up 1)

SOFTWARE (Pre-orders Only)**:
#09 XB1 PUBG (up 1)

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

PS4: 3 in the top 100 / 3 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5
XB1: 2 in the top 100 / 1 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5
NIS:  2 in the top 100 / 2 in the top 50 / 2 in the top 20 / 2 in the top 10 / 1 in the top 5

Switch having a great month so far in Dec! Ps4 still holding strong and even the XB1 is staying consistent. I wonder how sales will show come NPD with this being the Holiday period and so many things messing with sales.....in particular the B&M sales.

3 hours since last update.

HARDWARE:
#03 NS Neon (same)
#07 NS Grey (up 1)
#20 PS4 Fool's Edition (up 1)
#22 PSVR GTS (down 3)
#24 PS4 Pro (up 1)
#39 XB1X (up 1)
#41 PS4 Star Wars (up 5)
#42 SNES Classic (down 1)
#44 N2DSXL T+B (same)
#82 XB1 Forza (up 6)

SOFTWARE (Pre-orders Only)**:
#09 XB1 PUBG (same)

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

PS4: 3 in the top 100 / 3 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5
XB1: 2 in the top 100 / 1 in the top 50 / 0 in the top 20 / 0 in the top 10 / 0 in the top 5
NIS:  2 in the top 100 / 2 in the top 50 / 2 in the top 20 / 2 in the top 10 / 1 in the top 5