Professor Putricide - Good news, everyone!
Silver Hand Veteran - Handbuff + Light In The Darkness synergy
Cross expansion synergies?
Dark Iron Mistress - a straightforward card for small spell combos.
For those multi-spell combos.
Astral Call - board clear for Druids; you get more help the more you need it.
Elder Moonkin - Expanding the Druid board control kit.
Flash Kick! Flash Kick! (Stormwatcher's little brother)
Fight or Flight - Time to book it, Fido!
Toying around with the idea of stealth-ed token generation.
Something to try and fill the holes by nerfed FWA.
Brittle War Axe - punish for going face with weapons constantly.
Unyielding Fighter - a sticky minion with multiple synergies.
Exploring Rogue board-clear options.
Dalaran Advisor - You have much to learn!
Unearthed Knight - Stop digging him up! He's only gonna get stronger!
Improving discard with less obvious means than just 'choose your discard'.
Hunters can play around with spells too right?
Occam's Razor - the simplest solution to a problem; why decide between giving your hero or minion poison when you can do both?
Living Portal - Some support for the demonlock archtype.
Omen, warlock legendary - make a deal with the devil!
Bladestorm - Revenge replacement?
Velen version 2 - Burst Healing and/or combo potential
I feel like Recruit Pally is an almost viable archtype in Standard; just needs a little more help.
Defender's Mace - Simple little weapon for paladins; why not give heroes Divine Shield too?
Magic tricks in exchange for Coin.
There's Brann and Magni, but what about Muradin Bronzebeard?
Mannoroth, Warlock legendary - what doesn't kill you makes you stronger.
4 mana 7/7? How about 5 mana 7/7 AND a free weapon?
Shadowpriest inspired spell combo card.
Exploring more of the 'undamaged' mechanic Rogue has