Patch 5.3.0 (20-May-2013): Intimidation is now a level-30 talent available to all Hunter specializations and no longer learned by Beast Mastery Hunters at level 20.
Patch 3.3.0 (08-Dec-2009): If the hunter's pet is in melee range of its target, the stun from Intimidation will now be applied immediately instead of on the pet's next swing or attack.