It seems that Diablo 3 may possibly be getting a new character class. The rumor started when a piece of concept art, which is signed by the Art Director John Mueller, was found on the Blizzard Gear Store. Although the art was removed, the fans were able to save copies it.
The Diablo 3 concept art piece shows what appear to be two Necromancers raising the dead.
The male in the artwork is similar to Xul, another character from Diablo II who also appears in Heroes of the Storm.
The last time Blizzard added a class to Diablo was with an expansion. Maybe something will be announced soon considering that BlizzCon 2016 starts this weekend.