You know, this "0% clear FoS" is mentioned a lot - but do people really expect this will happen right after nerfs hit? Logically, guilds will finish their progress first, using whatever handicap they can, gear themselves to full and then go for 0% just before next patch goes live - assuming it obsoletes the achievement, that is. As such, I'm expecting that it's role is vastly overestimated and it won't be nearly as prestigious as some think.
Well, either way, Blizzard hasn't even finished releasing all normal mode content. It would be absurd to expect global nerfs that soon. That's what specific hotfixes are for, like nerfing Jasper Chains in 10 man.