Mizunie asks a couple of questions...
On the WotLK website, the designers talk about the "Scarlet Onslaught." Who are they and where did they come from?
The Scarlet Onslaught is the refounding of the Scarlet Crusade. Sometime after the events in Stratholme, Abbendis has taken complete command of the Crusade with a new band of lackies. She believes the Light has beckoned her to Northrend, so she rounds up every Crusader she has left and loads them on boats under the flag of the Scarlet Onslaught. There's other details to accompany this in Wrath, but they're way too cool for me to spoil this early.
Do we know anything on good ol' Deathwing?
Nope, not yet. I haven't seen much yet. It's possible we'll learn more in the Chamber of the Aspects raid zone coming in Wrath. It's been revealed that a Black Dragon is the boss inside there, though we don't know the details surrounding it yet.