It's a rather interesting class, full-support, very fast one - almost all skills have 0 cast time. It will not have any direct attack abilities (except ones inherited from previous class levels like Healer or Shaman).
There are 7 skills specific for Herbalist and 1 skill that will get new effects if used by a Herbalist (like Command cry for Archers).

The skill with new effect is Weakening. When Herbalist casts it - target's evasion and armor will be reduced.

Healing skills
- Recovery. Heals target 3 times (like regeneration).
- Resurrection - revives friendly character with 100% HP and mana, cast time - 1 second, can be used in battle (big cooldown)
- Serenity. Heals up to 5 targets. Herbalist creates a special aura which heals friedly targets and also increases effect of other HoT spells
- Lifebloom - restores much HP, HoT, can stack up to 3 times

Debuffs
- Concentration. One of the most interesting skills. Herblist chooses a target and curses it. After that Herbalist's party will deal increased damage to selected target. Several herbalists can't curse same target.
- Decrease of healing. Reduces healing received by target and slows it down

Passive
- Rage. Whenever Herbalist casts a spell he can get "trance" state, which resets cooldown for all abilities and 3 next spells he casts will not consume mana.