The way I have read it, that GW are releasing Daemonkin in this order.
Khorne (currently with Bloodthirsters)
Tzeentch (including plastic Lords of Change)
Nurgle (including plastic Great Unclean Ones)
Slaanesh (including plastic Keeper of Secrets)
As befits their current rankings.
Ultramarines are Pussies
Except Dark Angels, any chapter that sounds like a Death Metal Band can't be that bad.
