Current placeholders are:

Saronite Taskmaster:
If a better 1-mana Elemental is revealed, it will be an auto-include in this deck.

Countess Ashmore:
In this decklist, she has synergy with Saronite Taskmaster, Bloodmage Thalnos, [Hearthstone Card (Ziliax) Not Found] and Walking Fountain. She might get replaced by an even better card though.

Lightning Storm | Hagatha's Scheme:
The current Elemental Shaman doesn't play any board clear except one Volcano, thanks to the many pings ("Deal x damage") that the current Elemental package has. Depending on the future card reveals, we might not even need to play any board clear.

Storm Chaser:
It currently serves the only purpose of drawing Hagatha's Scheme. It would be more useful if there were more 5+ mana spells in the deck... Rain of Toads maybe? It will depend on the new meta.