This quest design is significantly better than Un'goro's. The objective is much more strategic, way less draw dependent, and the reward is strong but not a win condition in of itself like most of the Un'goro Quests were.
I hope they just flat out reprint Feral Rage. That'd make feral druids a lot better.
If Druid wouldn't be notorious for having no board clears besides Starfall (which IS a Choose card at least), I'd be more excited. You pretty much have to play nothing or just cheap cards for 4 consecutive turns, and can only profit from it from turn 6 onwards. Unless Druid gets numerous cards, that help the class to stabilize in the lategame and are ideally Choose cards, it's not worth it.
Just for the cards that are in Standard, I don't think I would play it. But it's too early to say more. The concept is interesting, and a permanent Fandral effect should not get underestimated, but there needs to be a LOT of support for this to give Druid a new playable deck.