An Explanation of Badge Gear
The new approach to badges (emblems) in Wrath of the Lich King is something new to us all. As more content is continually released, the gear you can purchase with emblems is upgraded, and in some cases the badges that drop in normal content, like heroic dungeons, is changed so as to grant access to this new gear.
What are we talking about by "badge" gear? In The Burning Crusade an item called a "Badge of Justice" was added to heroic boss loot tables. These badges acted as currency which could be used to purchase other items. Eventually, Badges were added to all raid boss loot tables and better and better items were made available to purchase using Badges. The problem was that a person farming Tier 4 content, like Karazhan, could get enough badges to buy Tier 5.5 equivalent gear with little effort.
In Wrath of the Lich King, the function of "badges" was changed. Now they're called Emblems of XYZ, though the "badge" term still sticks. As of patch 3.0, Emblems of Heroism dropped off of all Heroic dungeon bosses as well as 10-Man raid bosses. These were used to purchase comparable level gear (iLvl 200) to what is found in those instances.
There was also a higher level badge, the Emblem of Valor. Emblems of Valor dropped in 25-Man raids, and are similarly used to purchase comparable level (iLvl 213) gear.
When patch 3.2 released, all emblems were changed over to the Emblems of Conquest - this means that a person could simply do heroic dungeons and use the emblems to purchase iLvl226 items. A new emblem was introduced, the Emblem of Triumph, which only drops in the highest end content and can be used to purchase iLvl232-245 items.