Blizzard has made a couple clarifications on the official forums regarding the disenchanting and shattering hotfix and the Sinister Calling achievement. Bornakk had stated in the in-game fixes thread that "disenchanting and shattering has been slightly altered to provide more Infinite Dust than before," but Zarhym confirmed that the hotfix has been delayed. The fix will be applied sometime in the near future.

As for the Hallow's End achievement, here's what Bornakk had to say about it: "The text says that both a Hallowed Helm and a Sinister Squashling pet need to be 'obtained' for the achievement to be complete. More specifically, the pet needs to be learned and become part of your pet spell book for that part to be complete. The Hallowed Helm on the other hand needs to be looted by the character to fulfill that aspect of the achievement."