This Game Informer article has a lot of crucial info about Destiny's multiplayer. I'm not sure how much of this has been confirmed already, but a lot of it was news to me. Some of the main talking points:
- 6 player "fireteams"
- Low health/quick death. "When you catch a guy with his pants down, you take him down really quickly."
- MP will not be "unlocked" as soon as you put in the disc.
- Highly mobile maps. Similar to what we've seen of Titanfall, although not nearly as extreme.
- The adventure side of Destiny and the competitive side will be intertwined to the point where you will feel the need to play both.
- In game voice chat is only available to your Fireteam, but other forms of communication will be available. This is one of many attempts to isolate trolls from other players.
Also, when asked about splitscreen, this guy seems to get a little nervous. He answers it differently than all the other questions. It could be nothing, but here's hoping!