Strong cards that fit in legit decks
Menagarie Warden - Makes beast druid legit I feel, along with enchanted raven.
Enchanted Raven - Makes beast druid legit I feel, along with the warden
Cloaked Huntress - Absolutely nuts for adding even more pressure for hunters and can put a stealthed minion down before or after call of the wild (ready for the next one)
Medivhs Valet - A bit niche, but certainly useable in slower mage decks.
Nightban Templar - Given the other dragon cards added, this makes dragon Paladin worth trying again
Maelstrom portal - Shamans need a board clear and this has no overload.
Arcanosmith - Bit of a borderline card, but I think if you are going for control this card makes a lot of sense. Even in control warrior, it'll essentially put a stop to things on turn 4 and buy you time to a brawl.
Kindly Grandmother - Fuck this card, although that said it might not fit into decks just yet, becaues Hunter already has a few more "fuck this cards". It'll cycle in at some stage.
Barnes - I thought about leaving this out, but since N'Zoth is still pretty strong you might as well throw this guy in and see what happens. There is also the slim chance a combo deck will come from him, although it seems unlikely.
Book Wyrm - Although dragon paladin will be worth trying... I don't think this card will make a strong Paladin list due to space. Maybe a 1 of.
Prince Malchezaar - Needs the right kind of deck, but will certainly get some play.
Silverware Golemn - Even if discard doesn't work, and it doesn't, having this card in for a doom guard or soul fire just makes sense.
Netherspite Historian - A very strong card with annoying stats to boot. Even though I think dragon paladin will be the stronger choice, it'll get more play in dragon priest since priests have no other choice. The 1/3 stats work for early card draw, so it is a must include.
Moonglade Portal - Heal is always strong and 6 mana minions are generally nuts.
Avian Watcher - Seems ok and should fit into freeze mage.
Ok cards that don't really fit into decks or decks are not legit
Cat Trick - Wouldn't make it into a standard Hunter list, but you could do worse for the surprise factor alone given it functions as a counterspell to some degree (say against a heal).
Menagarie Magician - Just too clunky. Migth work in a joke deck.
Onyx Bishop - Too slow for contstructed.
Swashburglar - Actually pretty good, but pirate rogue isn't going to work and they already have full lists.
Deadly Fork - As above, not a card rogue lists need. Might be used in the future.
Arcane Giant - You'll see it in fun decks, but I don't think anything too serious. Needs way more spells than you would seriously have in your deck. That said, Barnes Priest with spells + these guys might be ok.
Firelands Portal - Too slow for constructed.
Ivory Knight - Too slow for constructed.
Etheral Peddler - Good card, but there isn't enough there to build a deck around.
The Curator - There are some fun ideas around this card, but none of them are as good as just running optimal cards.
Imp - I don't think discard will work and zoo has way stronger options.
Kara Kazham - It is ok, that is it.
Protect the king - Seems good, but anything it summons will be killed by the warrior who plays it. Even in a bolster deck, you'll essentially be wild pyro into muster for battle.
Pompos Thespian - It is only ok
Medivh - Far too slow except for some fun Druid or Priest decks. A good card though.
Babbling book - A bit of a whatever card.
Fools bane - I see this more of an arena card. But wouldn't be surprised if it works out ok.
Violet Illusionist - What kills this is the stats, it should be the other way around.
Blackrock Mountain Cards
Silvermoon portal - Paladin has way better 4 drops
Priest of the feast - Priest has better heal card synergy
Wicked Witchdoctor - Not a 4 mana 7/7
Spirit Claws - Not bad, but Shaman already has better weapons
Ironforge portal - Way too slow and 4 drops tend to suck
Pantry Spider - Just whatever
Arcane Anomaly - Just whatever
Moat Lurker - Amazing purify synergy. Which says it all.
Moroes - Warrior is in the game
Zoobot - This card is just getting silly
Purify cards
Runic Egg - Almost as bad as purify
Purify - Purify