Dreadknights are massive and awesome (they do look a bit awkward holding that sword...). Look at them! Also, it appears that there are so new and awesome dynamic poses with Power Armor Knights, with more tabardish looking things on them. Incinerators in the back look the same, but just (if you squint hard enough) looking at that front right squad you can see new poses and the way the swords are held is completely new and dynamic. It looks like one guy has two hilts on his back and is holding a two-handed gun. Tough to see with such a small picture.

The Grand Master and his retinue is about as cool as they get. I'm assuming the left most member of that squad is an apothecary (looks like he has something just above his head) while there are some Standards and perhaps a Librarian. There appears to be an Incinerator-Terminator in the back, too.

I'm. So. EXCITED!