So let's lay it out real simple for everyone, courtesy of what Zarhym said in a series of posts over the weekend:

  • Heirloom items currently do not provide an XP bonus in Battlegrounds.
  • Heirloom items should provide an XP bonus in Battlegrounds in Patch 3.2.2.
This is great news for those of us who like to power level our alts from 71 to 80 in the span of a couple days of playing via Alterac Valley farming. It's now going to go even quicker. That's a good thing, right?

The confusion of Heirloom's XP powers while in Battlegrounds is likely a result of the newness of the XP gains you can get in Battlegrounds. Eventually all that confusion will go away, and Zarhym's clear statements this weekend certainly helped with that.

Ok so at a time they didnt however after 3.2.2 they do.