YTD 2014 sales show PS4 with a lead of 5.9 million.  With three weeks left, the gap should increase to about 6.5 million.

Do you think next year's gap will be greater or less than than this years?

Xbox One has had a stronger showing in the UK & US towards the latter part of this year.  MS could decide to be more aggressive in EU in terms of pricing.

PS4 has more room to drop price in the US, Japan's baseline should increase, console launches in China (but that is unlikely to be significant).

What do you think and why?

Playstation 4 is loaded next year with exclusives nothing to exciting for Xbox One except Halo 5 (soory I don't follow Xbox that much inform me if there are more big titles). I don't think Microsoft will continue to sale it at a lost next year and the pricing will probably return to normal. Even with the clearly better deals the Xbox One only manage to slow down the world wide gap but haven't closed it all. 

That is 2014's chart.  I'm asking if the gap next year will be bigger or smaller when you just look at the sales from that year, not overall

YTD <> LTD

My bad honest mistake I wasn't paying enough attention. I still think the Gap increases. Microsoft won't continue to sell the Xbox One at a lost and 2015 is looking great for Playstation. 

X1 promotion ends by January 3 2015 and the lead for PS4 is poised to keep up. The gap has every chance to widen.

The gap will definitely increase. PS4 will have a much better year thanks to all of the exclusives, especially in Japan while XB1 sales will fall off a cliff with the price going back to $399 and no exclusives for a long time. That being said, if the price doesn't go back up to $399 then it'll make this a lot harder to call

Yes.

Quantum Break, Tomb Raider (Timed) and Crackdown

It all depends on if MS raises the price back or not.