I also hope there is a sufficient representation of Daemonology/Chaos magic, Necromancy, Rituals, and a ton of Hedgewizardry in the core system.
There will have to be some spells. I can't see a Warhammer game being released without cultists, necromancers, daemonologists, shamans, seers, or some other form of dark caster. If they are in the Bestiary, then they must have spells (in the form of spell card like entries). I'm guessing there will be a section in the back that contains the entries for casters so they don't have to be repeated. I'm also guessing the spell list will be limited and will be fleshed out in a supplement.
There was an example of a spell card in the 'Of Dice and Men' preview. The skill card symbols were further defined in 'Sample adversary spread from the Tome of Adventure’s Bestiary' PDF giving some insight into recharge, action type, difficulty modifier, check and requirements. Put the two together and it's not too hard to imagine how spell casting works.