Some little bits of information I have gathered
Bloodletters of Khorne are now strength 4, with special rules MR1, Scaly skin 6+, Daemonic and Daemon of Khorne. They have the daemonic gift Hellblade.... 14 points
I cant see any reference to killing blow but that dosnt mean they loose it as the sword may grant it.
Pink Horrors stats stay the same, special rules are Daemonic, Daemon of Tzeentch, Blue horrors of Tzeentch, and a unit counts as a level 1 caster.... 13 points
Yay Blue horrors of Tzeentch. No idea how it works but yay!
Plaugebearers are strength 4 Toughness 4, have the Daemonic gift plaguesword, and are Daemons of Nurgle, and Daemonic.... 13 points
Daemonettes get 2 attacks, and become Daemons of Slannesh + Daemonic for 11 points
Bloodcrushers are now special, 3+ a unit, the jugger mounts get toughness 4 and 3 wounds like the WOC ones, and are 65 points. With the scaly skin rules Daemons now have a 3+ 5++ save monstrous cav option!
Edit: might have this wrong, crushers may have 4+ 5++ save since the new WOC juggers only add +2 to the save
Flamers appear to have the same stats as the WD rules, and are 40 points. Special rules flames of Tzeentch, Daemons of Tzeentch, Warpflame, Daemonic and skirmishers.
There appears to be an option to upgrade a unit of Plaguebearers to have regenerate, and another option that if you score any roll of 6 to hit with a poisonattack, an additional strength 4 hit is made. Another option is upgrading poison to 5+