Blundell's big on PvE "balancing", from what I can tell. And by that I mean he likes tipping it in the zombies' favor. I have no idea why. They're lines of code. Remember when they nerfed a bunch of weapons in BOII's zombies and gave them godawful recoil for no reason?
Wonder weapons should never be nerfed unless they make the game too easy to the point where it's no longer fun. The only WW that really meets that criteria is the thunder bow, which has yet to be nerfed. Seriously, I have no idea why the devs feel the need to apply nerfs to weapons in Zombies - if a weapon's overpowered, so what? It's AI on the recieving end.