I love Luke. His posts are clear and a pleasure to read.... and they actually contain new info to the burning questions I had!!!
http://www.bungie.net/en/News/News?aid=12068
Summary of Key Points:
1. Normal difficulty is meant to be beat for any group that is willing to organize and cooperate. Likely has been nerf'ed this pass spring.
2. Two modes, normal and hard. Hard requires good execution, on top of cooperation.
3. Different sets of VoG exclusive drops for each class. 9 weapons to be obtained. Unique loot tables for each boss.
4. Private loots for everyone in raid.
5. Raid lock x 1 week. Expires every Tuesday. Cannot obtain loot on 2nd run within the same week. But can run a second time (?with different group).