First appearing as an 11-point Beastmastery talent, Master's Call is now a new baseline skill for Hunters in the Wrath Beta. With this skill, your pet will rush to your target and remove all existing movement impairing effects or stuns on the target, and cause them to be immune to them for 4 seconds. It can be used while you are stunned.
This is certainly a handy ability to have. In PvP, this should be awesome for getting away from Warriors and Rogues. In PvE, there's bound to be bosses and mobs with slow and stun effects, and this little skill could in theory, save a wipe.