#1 - Nov. 28, 2012, 1:21 a.m.
In the character battle pet API all references to the battle Pet ID (this is the unique id that refers to a battle pet in the character's journal have been replaced with a battle pet guid field.
So in the petSlots api we now have a "battlePetGuid" field which is the link to the "battlePetGuid" field in the pets api.
Sorry for the change.