One other big takeaway from Mists of Pandaria is that there is currently simply too much crowd control (CC) in the game, especially when it comes to PvP. To address that, we knew that we needed an across-the-board disarmament. Here's a summary of the player-cast CC changes:
Removed Silence effects from interrupts. Silence effects still exist, but are never attached to an interrupt.
Removed all Disarms.
Reduced the number of Diminishing Returns (DR) categories.
All Roots now share the same DR category.
Exception: Roots on Charge-type abilities have no DR category, but have a very short duration instead.
All Stuns now share the same DR category.
All Incapacitate (sometimes called "mesmerize") effects now share the same DR category and have been merged with the Horror DR category.
Removed the ability to make cast-time CC spells instant with a cooldown.
Removed many CC spells entirely, and increased the cooldowns and restrictions on others.
Pet-cast CC is more limited, and in many cases has been removed.
Cyclone can now be dispelled by immunities and Mass Dispel.
PvP trinkets now grant immunity to reapplication of an effect from the same spell cast when they break abilities with persistent effects, like Solar Beam.
Long fears are now shorter in PvP due to the added benefit of a fear changing the players position.