I agree it looks like a large expansion. I just put down the game after leveling (2) 30 characters when the VoG was released. I don't enjoy the PvP in Destiny and was super bummed by the lack of places to explore and fixed enemy positions around the worlds. Yes, i was another of those Bungie fans expecting something much more than was delivered and i'm just as much to blame for having overly high expectations.
That said i've been waiting for this DLC to see what Bungie had up it's sleeve. It looks like multiplayer fans will be stoked... and fans of the Hive encounters. The "taken" are just a Hive subset, correct? The Dreadnaught looks like more Hive Moon action to me personally. I'd love... we'll, something different and more expansive. Hell, i'd love if they did PvE and PvP content as standalone DLCs.
The Taken are very much NOT a Hive subset.
I'm trying to think of the best way to describe them. You know how in Halo you had Regular Elites? Like ones that ran around with plasma rifles? And then later on you found Special Elites that had swords? It's kind of like that. Every enemy in the game now has a Taken version that acts different than their regular version, and comes with a unique ability.
For instance: a Cabal Psion that has been Taken are called Gremlins. Gremlins have the ability to focus and literally split into two identical units. If left alone, they will multiply into swarms.
https://i.imgur.com/NDQMZaf.png
Another Example is the Cabal Phalanx. This unit likes to keep it's distance and has a sort of "force-push" attack that it launches out of it's shield hole thing.
https://i.imgur.com/HTQHTLN.png
Taken Dregs have a Ward of Dawn like ability but they can shoot out of their dark bubbles.
https://i.imgur.com/repttS1.png
Vex Goblins have some sort of Energy share ability:
https://i.imgur.com/9XpTkJ8.png
What makes this special is that up until now, you would never fight a Fallen Captain with a Vex Hobgoblin. You'd only find Fallen units with other Fallen units, Vex with Vex, etc...
Now, all 20 different enemy types can be combined into encounters. This combined with the fact that Bungie has included dynamic spawning (so that you wont see the same enemies in a strike every time), there is a much wider variety of enemies now.
Edit: This is an old Reddit thread that was trying to collaborate all the information on the Taken.
https://www.reddit.com/r/DestinyTheGame/comments/3a342f/meet_the_enemies_of_the_taken/