According to Crygil on the O-Boards, the Archavon encounter in Wintergrasp is going to undergo some changes.

Due to the high quality of the items attainable through the Archavon encounter in Wintergrasp, we are going to be making some changes. To keep the encounter in line with the rewards, we have changed the Raid Lock from a 3-day to a 7-day timer. Additionally, we have raised Archavon’s hit points, in heroic, to keep the quality of item on par with the challenge of the encounter.