Something that a lot of people choose not to address is the fact that PS3 also launched an entire year later which was a massive advantage for planting a healthy install base in NA, for the 360;
Now that the launches are finally aligned, we can see how these two competitors go head to head with nearly all things being equal. Can the X1 come back? I don't think so.
Can it, at the very least have a healthy install base here in America? Absolutely. There's just a lot of variables in the situation right now and we've all seen our favorite companies make decisions that left us scratching our head. So time will tell, but there's absolutely no way the X1 will outsell PS4 on a global scale.