The Neverwinter blog has been updated with the news that a brand new patch will feature some changes to PvP, most notably a new stat called "Tenacity". Tenacity, according to Cryptic, will be a crucial stat that is attached to PvP gear and will assist players with effects caused by players including control powers, like stuns and knock backs, critical hits, and damage.
If you are an avid PvP player, you’ll likely want to stack up Tenacity on your equipment to reduce damage from players who tend to be more offensively-focused. Tenacity will also reduce control effects on your character. Don’t forget that Artifacts and base attributes like Strength, Charisma, etc., will also increase your Control Resist.
Tenacity is not the only thing that will be changing how certain control effects work. Prone is being changed at its core and will now be affected by Control Resist, in addition to being much shorter against players at the base level.
Read more on the Neverwinter site.