The currency conversion coming with Mists of Pandaria is going to happen in three stages, and this is how we plan for it to progress:
With Patch 5.0.4 on August 28
Valor points will be converted to Justice points, and Conquest points will be converted to Honor points.
Neither of the resultant currencies (Justice and Honor) will have an enforced hard-cap at this time.
The current Arena season will end.
Players will no longer be able to earn Valor or Conquest points (bosses will drop Justice, Arenas will be closed).
Items formerly purchasable for Valor/Conquest will be available for Justice/Honor.
With Mists of Pandaria on September 25
Valor can be earned again.
Characters can earn up to 1000 Valor per week, and carry a maximum of 3000 Valor.
Daily quests, random Scenarios, random Heroic dungeons, and all levels of raiding will reward Valor.
Valor will be used to purchase ilvl 489 gear in Mists of Pandaria.
The Klaxxi, Golden Lotus, Shado-Pan, and August Celestials factions will sell this gear.
Revered reputation with each faction will be required.
Conquest will become earnable.
There is a cap of 4000 Conquest points.
Arenas and Rated Battlegrounds reward Conquest.
It will be used to purchase ilvl 483 gear from Pandaren battlemasters on the Great Wall.
With Mists of Pandaria, Patch 5.1
We currently plan to upgrade the Valor system as Ghostcrawler described in
Mists of Pandaria Looting Explained in the 5.1 patch, allowing you to upgrade your gear using Valor points. We’ll have additional information once Mists of Pandaria launches and we get closer to the 5.1 patch release.
