Well based on leaks there are 2 different PS4s coming as well, a 1 TB and what sounds like a slim
So I think that will be offset since the 1 TB seems to be 400 as well o.O
I'd say Playstation this month, because of the Batman Bundles selling like hot cakes.
I think XBOX next month might be August or September with Gears coming out against Until Dawn.

PS4 has that batman bundle going it, so I'm guessing the PS4.

I'm just going to leave this here:

"PS4 just continues to truck away; our preorder cap for the Batman bundles disappeared so friggin' fast though. Was almost comical. If the system really does get a price drop like so many are speculating, it would really be a hammer drop."

~ Abdiel

PS4, no contest. You have the huge Batman bundle, and the game itself, which has been heavily marketed to include exclusive content on PS4. I honestly think the last few NPD's have been a bit low for PS4 due to people anticipating that bundle.

PS4

PS4. And Sony will certainly announce a 1TB PS4 available in june

PS4 - Batman bundle

PS4. People like batman.

Makes sense though seeing as we have the results for May 

PS4 will win. Batman will be huge. will easy crush the 300k mark.
XBO will sell very well even if will probabily lose. E3 and 1TB SKUs will help. above 200k.
And the WU thanks Splatoon and (like for XBO and PS4) the E3 will sell a very good >100k.