"Some achievements come with in-game rewards such as tabards, vanity pets, and titles," the company wrote on its official site. "All of these rewards are purely cosmetic and just for fun, but you'll certainly stand out when you proudly display them."
Over 500 achievements will be available initially, with Blizzard noting that the list is "easily expandable." A new window displays the conditions for the various achievements, and also those earned.
The achievements are broken down into categories: Player-vs.-Player, Dungeons and Raids, Professions, Quests, Events, World Exploration, Reputations, and General.
Examples provided by Blizzard include giving out 10 hugs, collecting 10 vanity pets, beating every dungeon, or killing 50 enemy players in your faction's capital cities.
"Some achievements, including those that involve quests, honorable kills, items currently in your possession, skills (including professions), exploration, and reputations, will be applied to your character retroactively," the studio noted.
When an achievement is earned, nearby players and guild members are instantly alerted of the accomplishment. They will also be viewable on the web through the game's Armory.
Wrath of the Lich King is tentatively slated to arrive later this year.