For those of us who haven't the time to figure out what's going on with the meteors crashing onto Thundering Steppes and Nek Forest's docks, nor the gear to group up in Shattered Unrest... nor a single clue who Doctor Arcana is (has he appeared before?)... Could someone explain what's happening leading up to Ballads of Zimara?
I'm not sure what part (if any) Doctor Arcana and Shattered Unrest have to play in all of this. I have some thoughts, but I think it's too early. He has appeared before, in Blood of Luclin (you can find him in Recuso Tor in The Blinding.) I think that's his first appearance, although I could be wrong. As for the events near Thundering Steppes and Nektulos Forest, the meteors crashed onto the shore and into the sea nearby, causing tidal waves that did a lot of damage, but at least they didn't fall near major cities. During the prelude we learn that the rocks fell from a previously unknown island in the Overrealm - an island the hooluk of Whisperwind Isle know about, but are reluctant to tell us more about initially. In addition to the pieces of a formerly unknown Overrealm island falling from the sky, a particularly talkative hooluk (a Felfeather mage) on Whisperwind Isle also lets us share access to a memory of his clan by way of "imprint magic," which lets us actively view and participate in clan memories. The memory is of the founding of the Felfeather clan. That's pretty much it for the prelude event, at least at a high level. We're going to learn more once Ballads of Zimara launches.
Dr. Arcana was present in Planes of Prophecy, but only as the guy who would predict what the next PQ was going to be. His role in nearly every expansion after that was simply to be the PQ guy. Shattered Unrest is the first time he's shown up in a quest-giving role with any semblance of story, which I find rather jarring because the dialogue with him implies that we've interacted enough to understand each other's personalities, and that Shattered Unrest is causing him to panic.
I believe the above, which is from the official release news, happened because of the fragments falling from the overrealm. I have seen the good Doctor in every expansion since PoP to some degree. He also has some sort of thing at Solborm(spelling) that seems like it might be similar to Shattered Unrest but I have not done it.
It doesn't seem like it's been destroyed - more like displaced. But that depends on what Ultera is, exactly. I'm not sure that's ever been fully explained, even going back to Sentinel's Fate (where we first accessed Ultera itself when we made it to Odus.) I could have missed it, though. Some of the ghosts in Shattered Unrest make comments when you attack them, saying things like "I'm not supposed to be here, am I?" But I'm not sure if this is them understanding their new presence in Ultera, or if it's just them continuing to be confused about the Estate.
Yes, the lore implied by Shattered Overture is that if we were to travel to where Unrest used to be, we should now see a massive crater of debris. We know that regular Unrest will always be there, though. As for the confusion that the undead exhibit-- I'd like to think that they *knew* they were bound forever within the Estate, so whatever is capable of moving them to another dimension would cause them confusion as to why they're no longer where they died.