What are we talking about? In Icecrown Citadel, there's a mob in the Upper Spire region of the raid zone called Val'kyr Heralds. They summon other mobs called Severed Essences, which are clones of members of your raid. They don't use all of your exact spells, but they fit each class. With the exception of one (Focused Attacks), each of the unique spells Severed Essences possess have ended up being a new spell for their class in Cataclysm.
- Heroic Leap appeared in the warrior preview.
- Necrotic Strike appeared in the death knight preview.
- Replenishing Rains appeared in the shaman preview.
- While it isn't the exact spell warlocks are receiving, Rain of Chaos was the herald of green fire.
Unfortunately, the Severed Essences didn't hold any hints for today's hunter preview, and they don't have much to say about druids or mages either. We'll have to wait and see if Radiance Aura finds its way into the paladin preview.
World of Warcraft: Cataclysm will destroy Azeroth as we know it. Nothing will be the same. In WoW.com's Guide to Cataclysm you can find out everything you need to know about WoW's third expansion. From Goblins and Worgens to Mastery and Guild changes, it's all there for your cataclysmic enjoyment.