After looking through the steam forums and seeing Joodude's response along with everybody else's, it seems many are thinking this gun is somehow going to be just as powerful as a sniper rifle. The update made no mention of power (ie, damage inflicted), merely that the gun will be as accurate as a sniper rifle. No mention of headshots, or scoping, or one shot kills.
Imagine a spy with the ability to one shot a class at any distance. Even if it were the low health classes, this would be the most powerful gun in the entire game. A spy could cloak, move to a great hiding spot, uncloak, kill a low health class, recloak, and rinse and repeat. There's no possible way this gun is going to oneshot anybody. Sure, I don't like some of the changes Valve has done with a few of their unlockables, but I don't think there's any possible way they are dumb enough to release a gun that for the spy that can oneshot anybody.