MS is basically on pace to lose marketshare by 10 million units per year. If by 2020, the Xbox One is sitting at 80 million units sold and the PS4 is sitting at 100 million units sold, the consider it phenomenal sailing by MS. I don't see MS cracking 50 million units by that time though. They're a cake with crappy ingredients at this point. It's not going to turn out well.
Really huge exaggeration. The Xbox One is on track to having the current gen console percentage (MS consoles sold / all current gen consoles sold) as the Xbox 360 -- about 30% or so; Reason for that being due to how big of a drop Nintendo had.
I wouldn't call a console that makes up the same (or possibly higher) percentage of consoles sold within its gen as its successful predecessor "crappy".
The Xbox One won't be as dominant as the Xbox 360 was for its gen but it's not in a terrible spot at all.
Both Gears (a 2016 or 2017 title) and Halo (a 2015 title) are going to be dwarfed by Uncharted 4 when it releases this year. Not because the game will necessarily be better but because there will be close to 20 million more PS4's out in the wild by the time Uncharted 4/Halo 5 comes out.
This is pretty silly. All three games will have big launches and neither will be "dwarfed" by the other. Heck, Wii U games like Smash Bros. had big launches even though the userbase of that system will be very small in comparison to where the Xbox One and (especially) PS4 will be five years from now.