New Improved World XP
We’re improving the way we award World XP to World vs. World players! Now you’ll gain rewards for a much wider range of activities in the Mists – everything from destroying siege weapons, repairing walls, escort missions, and more.
Greater Variety and More Rewards in WvW
We’re adding new WvW daily achievements to the list you can choose from so you can earn World XP for playing the way you want. And every time you gain a new World rank, you’ll earn a bonus chest packed with useful WvW loot!
Dangerous New WvW Abilities
Become even deadlier in The Mists with new World vs. World abilities like Burning Oil Mastery or new ranks in Defense Against Guards!
Introducing Infusions and Ascended Gear in WvW
Now you can purchase Ascended rings and amulets and upgrade your WvW abilities with six new Infusions that give your character special WvW bonuses! Just speak to the new Laurel and Badge Merchants on each map
WvW Matchup Changes!
World vs. World matches are about to get an injection of variety! With these changes you can look forward to facing new opponents in new matchups and testing your world’s skill against more foes!
Thank you Arena.Net,
EDIT: source
https://www.guildwars2.com/en/the-game/releases/may-28-2013/