Who are the Fallen? What are their classes?

So who is this group known as The Fallen that run amok in the world of Destiny? What are their classes and what do they do? And why are they so cool?

Dreg

THE FALLEN CLASS: DREG

These relentless thieves seem driven by desperation and rage. They are crafty, but they usually give up their cover with their clattering and hissing. Most seem outfitted with some kind of shock dagger and pistol, and as far as we can gather, they seem to only have two arms, while other Fallen have four.

A Vandal from Destiny

THE FALLEN CLASS: VANDAL

The truths about the Fallen chain-of-command are still making themselves known, but Vandals appear to hold a higher ranking than the Dregs, and deadlier weapons, too. They often have long range capability, but, lucky for us, their weapons take time to charge.

Oh Captain, my Captain

THE FALLEN CLASS: CAPTAIN

Fallen run in packs, led by an individual Captain. There is no denying a Captain's might; they are the fiercest of the Fallen. There is this sense of tattered nobility to them. You can see it in the way they carry themselves. They think they're better than us. They believe that Earth belongs to them.

I freaking love that this guy has two swords. That means he's twice as bad ass as anyone.