The additional reward for completing the Dungeon Finder Call to Arms (called the Satchel of Exotic Mysteries) will be Bind on Account; able to be freely sent to other characters on your account once you receive it.
An error existed in the announcement regarding flasks and potions being picked based on your spec. This is not the case. If someone earns a Satchel of Exotic Mysteries, and if it rolls the random chance to provide a potion or flask, it will be a randomly selected. This helps ensure a broad array of available flasks and potions for all characters.
We also wanted to clarify, mounts that have a possibility to be found in a Satchel of Exotic Mysteries are found with the same rarity as if you had slain the dungeon boss that normally drops them.