Diablo III isn't the end of Blizzard's interest in its hellish action RPG franchise. Community Manager Brandy Camel has revealed in a video that the developer has "multiple Diablo projects" in progress, and it might have "some things" to show later in 2018. That won't just mean themed seasons like the ongoing Season of Greed, either. Further seasons are in the cards, but they're not the sum total of what Blizzard is working on.
Source: Diablo (Facebook)