Dawn of War Soul Storm has 2 movies up, showing the two new races.

Sisters of Battle
Sisters of Battle Movie

Dark Eldar
Dark Eldar Movie

Bah, was hoping for the Tyranids.

GW's modelling tips for Slaanesh.

With sections like:
PAINTING PINK SIMPLY TAKES A BIT OF PATIENCE
The color pink factors into quite a few Slaanesh-oriented color schemes. It looks like a tricky color to paint due to its bright nature.

SCULPTING LEATHER OVER ARMOR
Often, the followers of Slaanesh stretch leather over their armor.

SCULPTING FUR COLLARS
Other common ways Slaanesh Renegades distinguish themselves are elaborate fur collars and linings.

MODELING STUDDED ARMOR
Armor studs are yet another way to give off a Slaanesh feel within your squad of Chaos Space Marines.