13 days to go, and new information is becoming increasingly hard to come by. So, out of mostly boredom, I started doing some research on the only area I really haven't heard much about.
The Reef is a debris field in orbit around earth and within the Solar System. The Reef is inhabited by Awoken and Fallen who do not have hostility toward Guardians, as well as the Queen of the Reef.
It has been said you will walk around in third person like you do in the Tower, although your helmet will remain on.
The Queen is an Awoken living out in the Reef. She lives with many other Awoken there, but isn't as welcoming to Awoken born in the City. She is an important NPC who gives you missions.
Somehow, see seems to have some of the Fallen on her side.