Purists wouldn't be caught dead making use of Diablo IV's flexible new control scheme. Anyone's who has ever actually been caught dead because of an accidental attack when they meant to reposition might welcome it with open arms.
Blizzard plans to be transparent with the development of Diablo IV, committing to quarterly updates where the developer shares the status and coming-along of the game. In the first one today, Blizzard has revealed that it's giving the option to deviate from a Diablo staple: You can rebind attacks and movement off of the left mouse button.
This is semi-jarring news because Diablo lives on the left click. Click on every single spot you want your character to go. Click on every single enemy you want to attack. Keep clicking until those things are dead, and then click on the pile of gold they left behind.
It goes a lot deeper than just the left click. Diablo IV will let players reassign any skill to any key binding. With skills and movement fully flexible, it sounds as if Diablo IVgives you the freedom to make the game play however you want. But, and this is probably important for those aforesaid purists, movement and attack on left mouse will be the default.
Blizzard also confirmed that controller support will be included on PC -- another development that reads like heresy to anyone who knows the deep roots of Diablo. But, this is the first Diablo game that is being developed concurrently for both PC and consoles, and it makes sense that this sort of flexibility would be extended. Controller users also get the courtesy of fully customizing their bindings.
The last thing of note on the control front is that couch co-op now allows both players to access their own menus at the same time. Diablo III: Reaper of Souls brought the game to a screeching halt anytime one person used the menu. It's the biggest thorn in the side for cooperative teams. Now, an overhaul to that system should keep everything humming along.
Blizzard isn't yet ready to tell us the biggest news regarding Diablo IV: When it's going to launch. However, this new approach to detailing the development process means we won't be in the dark for more than three months at a time.
Diablo IV Quarterly Update -- February 2020 [Blizzard]