Apparently, marauders and chariots will cost a bit less, but chaos warriors will get an even bigger price drop. There aren't going to be any new models for the WD release, but there will be a plastic chariot, plastic warhounds and plastic characters boxes, as well as a plastic mounted unit (they were talking about new horses).
Then they started talking about a new core unit called chaos zealots. They're infantry (with poor leadership?) and two handweapons (they were talking about how many attacks you could get) who can be given marks to make them into thrall wizards (tzeentch), plague zombies (nurgle), or something frenzied (khorne). Slaanesh wasn't mentioned. The other guy said something about a magester, i don't know if that's a new character or a champion.
The redshirt asked about the daemon book, and daemon Princes are still around, and they let you take daemon units as special! Flayerkin are special, but they don't have their siege rules (no chains) and aren't moulder. There's a special unit of marauders, who might be called raiders?
Chaos trolls, chaos ogres, and minotaurs aren't in the list - they're in one unit, called chaos monsters or brutes or beastkin or something - i couldn't hear properly. They can be upgraded into trollkin, ogrekin or werekin.
Rare choices are spawn, hellcannon and GIANT.