Well in case you haven't noticed yet, the complete army selection is up on the GW site and an April 2nd date is listed as the release date for the new goodies.
There is also a "Getting Started" article in the astronomicon section that was interesting as well.
From what I read, the Dreadknight just sounds mean. 4 wounds, 2+ save, and pyshic powers on a monstrous creature.
The surprise for me was the Arco Flagellants. One of my favorite troops for the sisters army.
I just hope that the codex is somewhat balanced.