I've been playing a Cleric so I have to use the items dropped (or bought at a vendor) to utilize the arcane, dungeoneering and nature skills. I've successfully used the dungeoneering and nature skills numerous times and received crafting items. However, when I try to use the arcane skill, I am never given anything (3 or 4 times tried). I don't know if this is by design, or if this is a bug, but I thought I'd bring it up.
EDIT: Played after posting this and discovered that loot appears to be random and this wasn't a bug. Just had bad luck with arcane items that first day or so of play.