Halo and Gears can probably boost it above the PS4 globally for singular weeks (providing the PS4 doesn't also get a significant boost from something, similar to the PS4 v WiiU week with MK8 and WD). A significant price cut could also do it, providing it put the X1's price far enough below the PS4's.
Other than that i can't see it ever happening, not unless MS manage to turn things around. No idea how they will manage that though.








