It took roughly six hours, but I've now finished reading all the lore documents currently available from the Forsaken preload. (There's a whole lot!)

It is good. Very good.

Not only is it good in that classic Destiny way of "there's a good story scattered here or there", it appears to be good in the ways we always wished Destiny would be good. There appear to be multiple points where lore and story directly influences the game and story. Where the way the game unfolds will strongly support the lore. Where the challenges and tasks we attempt and accomplish have much greater meaning than getting some glimmer from a bounty or moving on to the next destination.

Below are a few levels of spoilers, from least spoiler-y to most. I'll mark each, but things will get extremely spoiler-y. You have been warned.

Background Lore & The Past:

We learn almost the complete history of the Awoken from who they were before their conception to their entire history all the way up to the current Destiny 2 era. It is extremely interesting and awesome.

We learn what Savathûn has been up to ever since she parted ways with Oryx.

Current Day Lore & Surprising Revelations:

The Drifter, aka the vendor who runs Gambit, is very much not to be trusted. He is actively toying with Darkness and has killed Guardians and raided shipments meant for the City. He is able to summon Taken creatures bound this his will. He is all around bad news... and we're going to be playing his little game...

It's a bit hard to tell, but Shin Malphur, aka the owner of the original The Last Word, may be keeping a close eye on the Drifter. Malphur and The Last Word do not appear to step fully into the spotlight during this season, but they might be getting set up to show up later.

It is pretty solidly revealed that the Hive worm gods and the Ahamkara are two different species that are both using / abusing similar methods to distort reality for their own gain.

By the end of the story it appears that Mara Sov will again be alive.

Ways Lore and Gameplay Are Coming Together:

Bungie has said that The Dreaming City will evolve on a repeating cycle, but this doesn't appear to be just some cheap mechanic where they move a couple of things around. Instead, within the story, The Dreaming City, which is heavily tied to the greater history of the Awoken, becomes trapped in a repeating time loop in order to save it from the Hive / Taken. The thought is that only Guardians with their paracasual Light will be able to alter their actions from loop to loop in order to find a way to defeat powerful enemies who would otherwise gain ultimate power by cracking the Dreaming City's defenses.

Raid / End Game Spoilers:

It appears that at least the first loop of the Dreaming City the final raid boss is a Taken Ahamkara... except it is actually a pawn of Savathûn's. By setting up this very powerful creature as the thing attacking the Dreaming City, she is luring Guardians of immense power to kill it... and then harnessing that power to fulfill her own ends... to conquer the Dreaming City. This also feeds into that time loop.

This is merely a guess, but I don't think being world's first in beating this Raid will mean much story wise because there are explicitly some things that require weeks of Guardian intervention to actually unlock. In at least one case, the Awoken have locked something down in such a way that only an ongoing and massive effort by Guardians will be able to charge and power it. It is possible that it takes multiple loops of the three week cycle for anyone to even attempt the final version of the raid.

There is even one hint (perhaps just a joke) that says soloing the Raid is the only true way to beat it.

All in all, the stories are great. Easily on par with the Book of Sorrows or the story of The Last Word or the interesting lore surrounding the Iron Lords back during the Dark Age. But more than that, seeing the well written stories that we've always had in Destiny actually play serious, tangible roles in our in-game actions and affect the plot we play through. That's something that hasn't happened very often or at an appreciable scale.

If I am interpreting this stuff right, Forsaken might bring Destiny to that merging of gameplay and story we always knew it could/should achieve.

I am very excited to see how this all plays out!