I can't wait to track down the new Live event. It appears that there is a new drop added to it, that people are not sure what it's used for yet (it may not yet have a purpose), and you can still get deaspected crystals to get your crown.
From what I have heard so far, there is an event triggered at each of the starter zones, this time there are imperials (someone mentioned imps in my ls), and once they are beat back (15-30 mins), a boss mob appears, and he has to be defeated. You then get a chest. The chest is per individual (similar to ifrit, or any of the other live events), and can contain potions (and supposedly this time even elixirs), drops, deaspected crystals, and this new drop (some sort of paper).
The current belief is that the event occurs every 8 hours. They ussually run from one major patch to the next.
And for completion, you do get a lodestone achievement.
In case people care. These events are like special events in that they can only be performed during their window, and once the event ends, it will never come back. These are the quests leading into the 7th umbral age.
I missed 2 of the first one (it was similiar to this, with imperials raiding aether camps, and you had to fight them off). I only completed one region, not realizing that they were marked for each region. But since then have gone through and done the rest (that I know of).
They are pretty fun, the rewards are nice, the exp is pretty good, and well, it's kind of fun to do these one shot quests (the last one seemed to have more story to it than this one).
Like all other live events, there is an NPC that announces the start of it in town. If you hear him (near the adv guild), that means that the event is starting. He will continue to announce until the event starts.
In the last event, it would automatically start once the event was full, or 15 minutes passed from when he started announcing.
The mobs were set for level 45+ players, and the number of mobs you fought were based on the number of people who joined. However, the boss was always the same strength (mid 50s with a lot of HP). Don't know if this one follows the same formula, but I imagine it isn't far off.