I think October will be quite close and could go either way.
But November/December I think PS4 pulls out a sizable margin over the XB1 (adding a few hundred K lead over these two months). Halo will have an impact on October to make it close, but I don't think it will be very long lived going into the holiday season.
Looking at how Amazon is trending so far and there's three SKUs in the top 20, two of which are bundles of huge multiplay games (Star Wars and CoD). This, coupled with the recent price drop, is really going to drive a ton of PS4 sales in the US.
Fallout 4 (another massive game) and CoD are also trending better on PS4 vs. XB1 in terms of software sales. I think at this point the momentum effect is just too big in PS4's favor. Microsoft did a great job last year of pushing the price of the XB1 low to drive adoption but it simply wasn't enough. I think Phil Spencer's recent comments reflect the current state of the market where trying to win US back in MS's favor just isn't a reality at this point, but they can still focusing on righting the ship and keeping XB1 a viable platform (which it is) in the US.
Microsoft's strategy with tomb raider has to be a little disconcerting for them. I feel this game will unfortunately get eaten alive and be completely forgotten about. Makes you wonder whether or not it was worth it from their end in retrospect. Hope it doesn't hurt the series' long-term viability, but this really should have been pushed back a few months in a lighter release window and should not have been exclusive. Square Enix took a bad short term deal that could screw them, imo....and for Microsoft you really have to ponder if it was even worth it at all. And I say this as someone that is really looking forward to Rise of the Tomb raider.