There's conflicting information on the chart.
On the one hand, the X1 IS overtaking ground on the Wii U thanks to Madden, and doing it fast. Then the other shoe drops; the PS4 has a commanding sales lead in North America, both in units sold in North America and Madden Sales. The X1 can't even hold its own market. Essentially, the PS4 now has so much inertia that any cross-platform release translates to a PS4 victory.
That will put much more pressure on Microsoft than on Nintendo. Microsoft and Sony are very much in direct competition, especially for the North American market. Nintendo is off doing its own thing.
For what it's worth, I will give the Wii U one more year to redeem itself. Zelda still isn't out yet, and while I don't think that will *save* the system, good Zelda and Xeno games will give the Wii U a moral victory of "we lost no consumer good will."