"Official:
Blizzard prevents addons from scanning pet abilities in PVP duels as of patch 5.2."
So now you just have to either know what every pet has as abilities, or know which types are weak/strong against their pets and hope they don't have attacks which are strong against you even if their pet is weak to yours.
Not being able to see the opponents moves before they use them just adds another layer of RNG to the system and I don't think that is particularly fun, it isn't strategy/fun/interesting to have to go look up every attack of every viable pet in the entire game along with it's cooldown.
My opinion, but what do you guys think?

