There's a new World of Warcraft patch on the PTR, and despite it not being huge, it does bring some juicy nuggets. First up, there's set to be some 15 years of Warcraft celebrations. Alongside that, there's Worgen and Goblin Character Model Updates, a new Alliance mount (bumble bee!), a new Timewalking Raid: Firelands as well as Party Sync and recruit a friend bonuses. I get the impression that this update is very much about house-keeping, and a new - at a grass roots level - to increase the playerbase, and make life easier for everyone. The biggest improvement is undoubtedly the Party Sync:

During this PTR we’re experimenting with a new mode that makes it easier for players in a party to do quests and play together: Party Sync. When players activate Party Sync, everyone in the party becomes aligned to the same quest state, including phases. By mousing over a quest in your tracker, you can see who is on the quest, what their progress is, and who’s ready to turn in the quest. There’s something else we’re going to try out on the PTR, a “replay” quest feature. This will allow players who have already completed certain quests to replay those quests with their friends for rewards that are appropriate to their current level, regardless of the original level of the quest.

The patch notes can be found here, and there's also a few screenshots of the new mount, and Worgen knocking about.