The main feature of this patch is the new five-player dungeon, Aetherblade Retreat. This limited-time dungeon pits players against the lightning-wielding aerial pirates known as the Aetherblades. Two unique boss encounters await players to test their skills, and new rewards, such as an infinite tonic recipe and a monocle, can be earned by those who succeed.
The third Guild Wars 2 novel, Sea of Sorrows by Ree Soesbee, also releases tomorrow; players can partake in an in-game scavenger hunt that ties into important locations from the book. Finding the 12 marriners' plaques scattered around Lion's Arch (and Orr) won't be easy, but players tenacious enough to uncover them all will be rewarded with a consumable worth five skill points.
There are many other exciting additions going into this patch, so check out the video preview past the cut for more details. (Minor spoiler warning to anyone who hasn't yet done the effigy lighting ceremony and subsequent investigation yet.)
[Update]: In the video, I mention killing Horrik first during the end boss fight of the Aetherblade Retreat dungeon. It should have said kill Mai Trin first as that is the correct tactic. My apologies!