If XB1 wins this NPD is it a big deal? If Sony are still in front overall what does it matter?
MS won December and it meant nothing in terms of momentum moving forward.
MS not only need to win March NPD but they need to by a massive margin, only a slight win after the massive push they gave with giving away TF in a bundle with a price cut would show that with MS throwing everything but the kitchen sink at it they would have effectively only reached parity with Sony who are still coasting on launch fumes and who have not begun the second push yet.
Anything but a massive win would be failure for MS and even then is no guarantee that they would keep any of that very expensive gain as momentum.