Free Action Potion

FAPs are great for flag carriers in Warsong Gulch. Use one as a druid right before picking up the flag, dash out of the room as cat, go cheetah and no one can touch you (except for Deathcoil). No rogue stunlock, no crippling poison, no frost shock, no hamstring.

Shifting in and out of bear while you;'re in the flag room will kill your mana very quickly and cause you to stay slowed enough as to die before you get out if enough people are on you. FAPs solve this problem.

Wouldn't this potion be good in PvE encounters with stun mechanics?

It says that it makes you immune to Movement Impairments and Stuns, which would mean that you would not be immune to Blind or Polymorph, but the AoE frost trap would not affect you.