Seems pretty well substantiated. Even if you don't believe the screenshot, the CVG interview video shows the same things just as clear, and its authenticity absolutely can't be questioned.
The most interesting thing to me is the killstreak selector in the bottom right. You've got 4 choices, all of which seem to be greyed out. You've got a progress bar that doesn't seem clearly notched like mw3, so it probably isn't just raw kills/points. You've got 4 lines, which probably correspond to the level of power you need before you can activate each individual streak. It'd be reading into it a bit to unequivocally declare that they're definitely using the street fighter-esqe power bar where you decide between many weak or few powerful streaks....but this certainly doesn't rule it out. For one thing, the semicircle that the power bar can fill up seems to extend way past the 4 lines, which leads me to believe you can bank a lot of power, and using a streak eats away at your bar up to the line of the streak you chose. Also, the lines are in different positions in the MP screenshot vs interview screenshot, but it looks like the same streaks...so maybe some perk or other factor such as whether you're winning or losing, or how many streaks you've already used, etc, may be influencing how often you can use them....which makes it even less likely it's based on a raw number of kills/points. Its not even that the lines have moved up, but the proportions b/w them have changed, so Hardline reducing by one point doesn't explain it. Really psyched if this means what I think it does.
The gun is clearly an MP7 than looks just like MW3...with some sort of under barrel attachment? In the video one of the guys is clearly firing a SCAR, which looks ripped right out of MW2/3 down to the reload animation. Both are probably just placeholders.
Also of note:
TDM and Domination are back (big surprise there).
Selectable classes are still in...when he pauses the game you can barely make out "change class"...another shocker, I know.
There's a timer and streak icon next to the map, bet that's shows time left on a UAV/streak. Perhaps its actually the enemy team's streak, since if its your UAV, you'd prob see more than two enemy red dots. Either way, a solid common sense addition.
Assault shield....meaning riot shield??? Its taking up the whole left half of the screen, and is 100% ripped out of the CVG video, so it's legit...maybe of note is that it doesn't say X to swap for shield, so it might not be a selectable weapon, but something environmental or temporary like a stationary turret.
This HAS to be legit. Generally, nothing looks radically changed, still looks like cod.