Grey Knights are out and boy do they look awesome!
Definately going to check out the book and compare to what I usually use in my Dark Angels. At the very least I will probably pick up a box of Grey Knight terminators to use as Belial's command squad as the models just look fantastic!
The Dreadknights look cool too, though I don't like the exposed pilot, but nothing a little plasticard couldn't fix I think. Really reminds me of the Aliens power loader.