So, my original guess was that the DSD was dead, but as people have pointed out with the All, it seems as though it's still kicking.
A lot of people are speculating that the second voice we hear in the trailer is "Mother." But when Kralk said "Mother" it could have just as easily meant that he was rejoining her, not that he killed her or was calling out for her for help. This would make me think that he was joining her in death.
With the Glowing Orb in Malchor's leap looking so similar to Kralk's heart, could it be that the golden orb is what's left of Mother? The orb as commented by the inquest seems to resist Zhaitan's corruption but also corrupts the land around it, turning it into metal. What kind of artifact would have that effect? And if it were a remnant of Orr, why wouldn't there be anymore information on it?
It definitely seems like it's related to the elder dragons. It may not necessarily be "Mother" or the aftermath of her, but could be a remnant of a previous dragon rise. Odd that it seems to be in this position after the rise of Orr, because if it was there before it had to have shifted with the rising of the island. If it was there after, why wouldn't there be any information on it?
If it IS an elder dragon heart, I wonder why it's just been sitting there and Zhaitan never seemed to express interest in it. It's obviously a pretty significant source of power, you'd think Zhaitan would have done something with it. Or they did, and this is just the residual magic left in it.
Such a mystery and it's odd we haven't gotten any information on it, given how much has happened since the core game.
I may have also just lost my sanity because I converted 1000 grains of coarse sand into golden sand in the hopes that it will someday have a purpose, or I'll magically discover one.