I'll play it. My hope is that it is closer to the feel of D2 and Not D3 as much. D3 is ALL grind, little story, arcade style running around. It never made me feel lonely or hopeless the way Diablo II could. I think a lot of it is just down to visual design. Having every corner completely lit up and no light radius made the game seem less horror and more Call of Duty.
I think adding in some elements from the modern horror genre would go a long way. Lighting effects that play with your mind. Maybe you thought you saw a person in the corner, but it was gone before you really locked onto it with your eyes. Cthun like whispers and the sounds of distant screams and wailing just under the howling wind and creaking trees.
As a WoW player who refuses to use add-ons and macros, I'd like to see the game reward reading and investing into the lore. I don't want the game to flat out tell me "Go to this part of the map and click this. Yay, you did it!" I want adventure and mystery. I like having to solve a riddle to figure out where the secret path is or working a puzzle down to get a door open. Without these, there isn't going to be much replay value for me. Remember when the maps were randomized in D2? We need that again. I don't simply want to follow orders and play a drawn out Simon Says in Diablo, I want to explore and have to find my experience. D2 was about exploring and paying attention to the story a bit more. Diablo 3 was about finding the same legendaries each play through and finishing your list of chores each season.
For extra replay value, bounties could have story-lines woven into them. Instead of "Go here, he's south of you, you clicked him 4 times and he died, return to base" they could make it a short story. Talking to the locals, you are told of a caravan that was supposed to arrive weeks before, but has not been seen since they last reported in some far off town your map doesn't lay out for you to find. Chain quests that require thought and attention to wording and context clues to complete, not pending if you can follow a glowing arrow on your map.
More events like the Darkening of Tristram would be welcome. Especially if they change per player. Maybe MY adventure had me slaughter 40 zombies and dig through their remains for the ring of a noble to use as a key to unlock a vault, and YOUR adventure led you to sail out to an island shrouded in mist and redirect the waters of spring that powers a waterwheel and activates a light house. Depth, purpose, and story. Not, 4, 3, 2, 1, 4, 3, 2, 1, potion, 4, 3, 2, 1, right click, loot.
Diablo II + Myst + Hereditary.