The hive are trying to take control of Rasputin so they can bombard the ice caps with warsats and free Xol who has been trapped beneath them
Evidence:
This wouldn't be the first time the hive have tried to take control of Rasputin
The frequent strikes from warsats is melting the ice caps
The trailer shows a shadow bursting out from below the ice that matches the description of a worm god
[spoiler]also the description says worm god[/spoiler]
There is an exotic warlock helmet with Xol in the name (Xol is one of the worm gods)
What do you guys think
Nope.
The hive are only free on Mars because Rasputin has activated that protocol, causing warsats to crash down on Mars.
The warsats are breaking up the ice, causing the ice caps to melt, in turn freeing the hive that have been frozen under the ice.
These are VERY old hive, as you can see in the reveal trailer, there's also hive tomb ships frozen under the ice.
I'm more curious about how they became frozen in the first place.
But yes, these hive must be incredibly ancient if they are doing the bidding of Nokris, who as we know, there is virtually no proof of his existence in Destiny 1.
I'm really curious to see how the lore/story will pan out!