Here is a quick summary from the Aionsource forums.
To summerize, the first change was in regards to the Fortress Sieges. Defending forts are possible, but to make it less hard and competitive, some changes have been made to the defense system. Also medal distribution has been changed.
Second, a new UI option was added. This change will lessen the crashes during the sieges and areas with many players.
The third is among the most waited changes ever, which is flying SM pets. Until now you couldn’t have your pets flying, but now you will be able to fight aerial battles with your pet.
Lastly, three new costumes were added. They are: traditional American, traditional Russian, and traditional European attires.
I’m really looking forward to the flying pets.
If you want to read the full translated notes check out the post here.