I remember when people said priest was gonna OP when dark cultist came out. Talonpriest... I don't think this does that nor does it make priest a curve god. 3/4s 3cc have been consistently overreacted to and overrated in the past.
Impressions of the first set of cards revealed:
Piranha Launcher - The text seems good. Summoning 1/1 beasts for Hunter is usually relevant. The mana cost kills it though. 5 mana for a 2/4 weapon? Unplayable.
Lotus Assassin - He's like a slower, weaker Giant Sand Worm. Unplayable.
Kabal Talonpriest - A strictly better Dark Cultist, which was one of the best 3-drops in the game. Overpowered.
Kazakus - His condition is going to require a very specific type of deck. But the reward seems well worth it. He, like Reno, will be relegated to one deck type, but I think that deck type will be viable. Playable.
I Know a Guy - Most taunt minions suck. Meh. Unplayable.
Meh, pretty negative gutshot!
Piranha launcher is like assassin's blade with a twist. I think hunter would run assassin's blade. This one leverages beast synergy. You still get 8 damage but you also activate your beast synergy cards without paying mana on subsequent turns.
Lotus assassin is NOTHING like giant sand worm. GSW is bad because it's so expensive and needs to survive a round to even start attacking. Lotus assassin has stealth, almost guaranteeing it survives to attack. Then it can't be finished off with removal if it trades.
Kabal talonpriest is not a strictly better dark cultist. DC could be played on an empty board on curve and then if it survives a turn, you can buff a 4 drop. Talonpriest requires you to already have board presence, something that is difficult to guarantee early on, especially as priest. And you're buffing a 2 drop on curve, much weaker than buffing a 4 drop. Plus no n'zoth synergy.
Hard to judge kazakus without knowing more information about what spells you can make.
I know a guy - since warrior cards will be favored to show up, you're getting ferocious monkeys, that 2/6 with enrage that is very playable, and the 3/2 taunt that gives another minion taunt. None of those taunt minions suck imo. Then you have a spread of okay neutral taunts, with a sprinkling of bad taunts.