In addition to the previously announced changes coming with the weekly reset for PvE and Raid Tuning, Blizzard posted a list of PvP changes. These changes address PvP outliers like Shadow Priests and Havoc Demon Hunters.
Player versus Player
Classes
Demon Hunter
Soul Rending leech bonus reduced by 40% in PvP Combat.
Havoc
Glimpse (PvP Talent) damage reduction reduced to 35% (was 75%).
Essence Break damage bonus for Chaos Strike and Blade Dance reduced by 37.5% in PvP Combat.