First round of spoilers have given me some cards I want and reignited interest in cards I don't have from older sets.

Shock lands will probably be a must. I'm proxying them for many of my decks since I only bought 2 sets. Guild pairings are Overgrown Tomb, Sacred Foundry, Steam Vents, Temple Garden and Watery Grave. Next set it's expected to have the non-Guild colors.

Underrealm Lich seems like a good inclusion in a graveyard based deck. I don't think this belongs in my Meren deck since I will be dumping more stuff in the graveyard than I care to, but paired with a commander like Muldrotha, the Gravetide and cards like Crucible of Worlds, it might make a good graveyard deck.

I have a creature deck and an artifact deck with heavy graveyard themes and introducing another to my playgroup with Muldrotha would require some graveyard hate. Leyline of the Void is a great graveyard hate card and is something I feel belongs with Bojuka Bog in almost any deck with black, but is way too expensive to get more than 1 of currently. I may proxy it for testing since it may swing the game too much.

Rotation is also happening. Good time to grab some Kaladesh and Aether Revolt cards as they will be cheap as people are selling off their Standard cards.

Cataclysmic Gearhulk - Boardwipe for Daretti Nissa, Vital Force - Card draw for Atraxa Disallow - Cancel for 1 and 2U. Usable for multiple decks Walking Balista - Beater for Atraxa with counter Shenanigans. Scarab God - If I ever build a zombie deck, this is pretty much the best commander. At minimum in the 99 if I picked Gisa and Geralf for zombies. Firemind's Research - Spell slinger enchantment if I ever build another storm deck Assassin's Trophy - Buy a bunch. Will probably become expensive due to the colors and capabilities. Response // Resurgence - Additional combat steps for Kaalia Chromatic Lantern - Reprint. Worth picking up a few when it releases for my remaining decks without it.