There are several rumors that suggest a new Diablo game will be announced on November 4 at BlizzCon 2016. While some believe a HD remaster of Diablo 2 is incoming, judging by some vague evidence, a whole new installment seems more likely.
The first rumor rumor comes via some promotional swag gifted to YouTuber Rhykker. As he explains in the video found below, a BlizzCon promotional pack contained a few die, one of which was a D4 - a four-sided die. That's enough cause for the Diablo fanbase to get excited, but it also turns out that the numbers on the die were misprinted: instead of three "1"s featuring at the bottom of three sides of the die as usual, there are two "1"s and a single "4." In other words, the misprint reflects the starting date of BlizzCon 2016 (November 4), which just so happens to appear on a "D4" die.
In other news closer to the source, both David Brevik and Bill Roper have appeared at Blizzard's California premises this month. Brevik was project lead on Diablo 2 and Roper is a former president of Blizzard North, and senior producer on Diablo 2.
Brevik also tweeted this recently:
It's likely that finds will discover the truth behind these rumors on November 4.