Okay pelase bear with me guys because I have a theory. In the trailer we know that we are close to Morrowind because of our set location on Solstiem. We now understand that the plot will greatly involve Hermy Mora, not only that but we see a mysterious large shard in the trailer that looks to be a vital piece of the story. Now. During the main quest in skyrim we come across Hermy while Septimous believes he has encountered the http://elderscrolls.wikia.com/wiki/Lorkhan of Lorkhan. now let me draw your attention once again, we are near Morrowind. Hermy Mora is involved with us once again. And we have seen a mystery shard in the trailer, now I am not saying that this is fact. But could it be that the first dragonborn found the location of the Heart Of Lorkhan in Hermys realm of Apocrypha? And was power hungry for immortality?

Also the heart of Lorkhan does look very crystal in http://elderscrolls.wikia.com/wiki/Heart_of_Lorkhan

Oh wow thats good speculation. I gonna do that quest again and actually listen to what he said.

by large shard do you mean the large pillar like stones that are glowing and jutting out of the ground?

Well yes and no. The people in the trailer were building around a large stone/crystal. The shard begins to glow and burst near the end. We have two angles of the item. Though no conclusion as to what it is.

really doubt thats a piece of the heart
it just looks like its one of the skaals sacred standing stones

Well, it would coincide with the KillMoveDLC02RipHeartOut animation.. ripping the it out of whatever machine was using it as a power source

Maybe the/a Ballista Centurion is using it.

Again, is this the 'shard' we can see at 0:38 in the trailer?

EDIT: or the 0:54 one?

The Heart of Lorkhan was destroyed...
I know this because I destroyed it in 2005. I saw it be destroyed, and watched Akulahkan explode.
Twice with Keening, thrice with Sunder. Or the reverse.
I know it worked, because when I killed Dagoth Ur right afterward, he stayed dead.

Yes, that would be the one. It is possible as well that Bethesda just redesigned the heart. Although I have no proof on the matter.

Well, I think it's possible but unlikely. 1. They look like standing stones of sorts rather then the heart, 2. Those that know the lore of MW inside out will and have find ways to say it's been destroyed already. Interesting thought though

The heart is gone, destroyed, bye bye, along with Dagoth Ur

Your probably right, though not the standing stones. The massive rock in the middle of them. Also did Hermy just deceive Septimous into believing that he was looking for the heart? Because as smart as septimous is, wouldn't he have known that the heart was destroyed?

...Daedric Princes are [censored[holes like that.

xD Agreed.

It is gone, but it is not destroyed - the Nerevarine removed the enchantments placed upon it "freeing it", but didn't destroy the thing.

Though I don't think we'll be seeing it.