Elidroth just posted again.
"Since the content for the past 3 expansions has been tuned with this functionality in place, here is the team's decision on this issue:
* The existing AA's will be refunded and removed from the game.
* Warriors, Shadowknights, Paladins, and Rangers will receive a new AA that specifically gives this immunity.
* Monks, Rogues, Beastlords, Berzerkers, and Bards will get this immunity in a triggered, short duration version.
* Beastlords, Magicians, and Necromancers will get a version of this that can be applied to their pets.
This will most likely be in place for the June patch. Look for it on test sometime in the next 2 weeks.
"