via TastyTaste on Blood of Kittens
As it turns out there is some valuable rules information from the GW Battle Report here is a quick run down of those insights.
*Deamons of special rules are the same as the ones found on the Deamon Princes in Chaos Space Marine codex
*Burning Chariot of Tzeentch has Torrent AP3 Flamers along with second mode with high strength for vehicle killing.
*The Skull Cannon of Khorne is Large Blast S8 AP4 or 36" range
*Standard Deployment is back for Deamons along with normal Deep Strike
*Plague Drones have upgrades to get 3+ along with at least Strength 4
*Daemonic Rewards random chart three tiers (50 pts to roll)
*Herald Loci buffing powers for same god units (Icons of Deamons)
*All Heralds (minus Khorne) can be psykers and you still can take two for one per HQ
*Warp Storm random (2d6) powers that effect Deamons every turn of the game.
*Tzeentch Gets Divination (HUGE)!
*Soul Grinder has Skyfire
Those are the big ones I could gather I know others on the net have posted their own lists from the White Dwarf.
If you want a closer look at some of the Deamonic Rewards here is a pic.