We've had our first looks at the new Imperial Guard, and their shiny new name the "Astra Militarum."
Why Astra Militarum? I'm guessing it's because it'd be really tough to copyright the name "Imperial Guard."
Without further ado, here's the Codex cover (these shots snagged from facebook)
For me, the most exciting leaked shot is the new Tempestus Scions. I believe these are the new Storm Trooper unit, which makes me wonder what'll happen to Kasrkins.