Blizzard registered a new trademark The Dark Below caused the Blizzard community hot discussion. The trademark (via Massively) does not give any further detail regarding what The Dark Below may pertain to and a company representative was not immediately available to comment.
A Gamescom invitation sent to media last month said, "We're making a special announcement that's sure to capture the attention of the Heavens, Burning Hells, and all the shadowed places that lie between."
So what does this mean? If we break it down, it could be an expansion for World of Warcraft, Diablo III, or Starcraft. Blizzard has a tendency to break out new content after a while and stagger releases, so most recently they released Mists of Pandaria for WoW and Heart of the Swarm for Starcraft. By process of elimination, Diablo III needs some expansion loving.
During an earnings call earlier this month, Blizzard Entertainment president and cofounder Mike Morhaime said the company's Gamescom announcement would be related to Diablo. Additionally, it is said that Blizzard may be releasing more information at Gamescom in Cologne, Germany from August 21st to 25th this year. We could be hearing more information on both The Dark Below and Project Titan.