Thats a good thing nerfing the current exagerate situation of dmg Is needed .
The main reason Is the stack of each proc released.
But i disagree with some nerf applied on the classes.
I think that the situation will be under control Just right now if insane procs Will be nerfed (arcane 76-71 armors,mitic 76 set daggers,axe,aegis,staff).
Then i think to introduce a new passive table named advanced passives.

Those passive focus on flexibility of each class, right below i give some example.
Numbers Need adjustements, mage ones are very strong.

TANK
passive 1( dmg dealer) rogue like
5 level
Each lvl gives +25dmg +10% dmg +5% strg -10% armor -10% hp
Passive 2 (taunt support) mage like
5 levels
Each lv gives +20% mov Speed +8% haste
+2% mana and healt/sec, skill cost -8%
+5% taunt

MAGE
passive 1 (rapid Fire skills) rogue like
Each gives +8% haste +30% skill dmg
Skill cost +20% +5% crit -20% mov speed
Passive 2 (gigantic mage ) tank like
Each gives + 15 all stat +5% all stat +5% crit + 6% Dodge +10% armor +10% hp +10% mana
+ 20% cooldown skills.

ROGUE
passive 1 (pet support) mage like
Each gives pet dmg+40% pet crit +5%
Pet cooldown - 5% pet skill duration +5%
Skill cost -8% + 2% healt and mana/sec
Passive 2 (brawl) tank like
Each gives +10% hp +10% mana +10% armor -10% Dodge +5% all stat, skill dmg -10%

Those passive Will be used to give a different look for each class into someone else depending on your playstile.
Suggestion below.