A few tidbits:
Treason of tzeentch has an entirely new purpose. No more mind controlling your opponents unit/model to fight for you. It's now an effect that exists elsewhere in the game, but isn't terribly common.
Gaze of Fate is no longer a free reroll, but now interacts with Warp Storm Points in an interesting way.
The Slaanesh discipline is (imho) almost all good stuff. Fighting in the psychic phase is gone, true, but most all of these spells have a time and a place they want to be used.
Khorne, obviously does not have psychic powers.
That said here's a brief sampling from Tzeentch and Slaanesh (edit: and nurgle). Please note again that the wording on some of these is not final, and we may see changes between now and release.
Two Tzeentch Spells
Bolt of Change (7): Choose a unit within 12" and visible to the caster, roll 9d6. Each 5+ is a mortal, for each model killed that unit takes an additional mortal wound.
Infernal Gateway (8): The closest enemy within 12" and every enemy within 3" of them takes d3 mortals. On a 12+ they all take 3mw.
Two Slaanesh Spells
Symphony of Pain (7): Choose a visible enemy unit within 18", they have -1 to hit and -1 to wound in melee
Hysterical Frenzy (7): Slaanesh CORE unit within 18" gets +1A and exploding 6s in melee.
Two Nurgle Spells
Nurgle's Rot (7): Roll 2d6 for each enemy unit within 6" - if you beat their toughness, they take d3 mortals. If you double their toughness, they take d6 mw.
Miasma of Pestilence (8): Pick an enemy unit within 18", it cannot preform actions, any actions it is currently performing fail, and it loses obsec."
