Another new PTR build has gone up with the build number 10623. With it comes a few changes to achievements mostly for Icecrown Citadel but there is a very interesting one mentioning a new fishing event that changes the old Master Angler of Stranglethorn achievement.

You can read more about them after the jump.

Disclaimer: Some of the numbers used below are either placeholders and some of the achievements may or may not make it into the live patch.

Changes:

Master Angler of Azeroth - Win the Booty Bay fishing contest or the Kalu'ak Fishing Derby. (Previously: Master Angler of Stranglethorn - Win the Booty Bay fishing contest.)
Realm First! Fall of the Lich King - Participated in the realm first defeat of the Lich King in 25-player heroic mode. (No title) (Previously: Realm First! Light of Dawn - Participated in the realm first defeat of the Lich King in 25-player heroic mode. Title Reward: the Light of Dawn)
The ??? - Defeat the Lich King in Icecrown Citadel in 10-player heroic mode. Title: the Frost Ender (Previously: The Frost Ender - Defeat the Lich King in Icecrown Citadel in 10-player heroic mode. Title: the Frost Ender)
The Light of Dawn - Defeat the Lich King in Icecrown Citadel in 25-player heroic mode. Title: the Light of Dawn (Previously: The Kingslayer - Defeat the Lich King in Icecrown Citadel in 25-player heroic mode. Title: the Frost Ender)

New Achievements:

The Sword in the Skull - Recover the missing hilt of Quel'Delar, draw the blade from its resting place, reforge the weapon, purify it in the Sunwell, and present it for your just reward.
The Frozen Throne (25 player) - Defeat the Lich King in Icecrown Citadel in 25-player mode.