Returning Keyword: Magnetic

Zilliax , Reno Jackson , Finja, the Flying Star will be in the coreset

Seeing as they are bringing Mech Mage back they are most likely giving it support in the coreset. Magnetic would be a good way to boost it's strength. 

Blizzard has also said they want to go in a more board based direction this year.

One of the best board based cards ever is The Lich King So I'd bet he will be in the coreset as well.

Rogue secrets are rotating I could see Rogue getting a couple secrets back in the coreset and of course some pirate synergy

General Coreset Direction:

Hunter: Deathrattle package

Warlock: Zoo Package

Mage: Mech Package

Shaman: Token Package

Priest: Spell Package

Paladin: Mech

Druid: Beast

Warrior: Midrange/Control

DH: idk lol

Neutral: Mechs, Murlocs, Nagas, Elementals, a bit of everything