On the Devline chat, Swen answered the question (which hopefully he understood), and said that the passive abilities for certain proposed skill groups would come from Talents.
- Bard - "Weave Lies into your Tales"
"Influence NPC" Those seem rather vague, kinda like they give you new dialogue options. - Summoning Master "Summon more than one extra Ally" Does that apply to any of the possible summons, or only to specific ones in the summoning master tree?
- Juggernaut "Get stronger as your health drops" "Dual-wield Axes"
- Alchemist "Improved benefits from potions"
That's actually pretty good news, in fact, because it means that even if the way to make full-fledged skill trees are not picked, some of these Talents could be added to the game anyway.