Blizzard has said they plan on having two expansions. What would you like to see?
I’d like to see a Hell overworld (well, underworld) about the size of the current one but it changes randomly- maybe every day. Would need to be done so it doesn’t feel like you need to explore the whole map constantly. The expansion after would take place in Heaven. I want to kill God for loot. He fucking owes me.
I’d like to see the Paladin/Crusader and especially the Amazon make a comeback. A demon summoning class that has more temporary pets (because you sacrifice them for power) could be cool. Maybe add some witch doc stuff to it.
I might be pulling this out of my ass, but I somehow recall that some of the wizard abilities in D3 implied telekinesis. Which then implies that psychics could be real. I think you could combine it with some aspects of like 1800s spiritualism or aesthetic mysticism to nail down the theme.
I think it would fit right in to the gritty world D4 has made. Maybe be a sect of Ivgorod, which gives us a reason to go there for the first time and maybe back to Arreat to re-settle the clans.
Edit: Oh! I also forgot to mention how it could be so environmentally interactive. Like telekinetically throwing random environmental objects at enemies or slamming enemies against walls in tight spaces.
For some reason this also made me think that whips should be a weapon class. Rogues, the psychic, & sorc could use them.