Possible Diablo 3 expansion ‘Reaper of Souls’ being teased

Yesterday, it was discovered that Blizzard had filed a recent trademark for "The Dark Below." We weren't quite sure what it meant at the time, but now a new page on the official Diablo website has been revealed, teasing something that appears to be called "Reaper of Souls." Are the two related?

The page shows an image of a shadowy crypt-like entrance with a quote from the Book of Tyrael that reads: "Death, at last, shall spread its wings over all."

As Joystiq points out, searching the source code reveals that the image has the filename "d3x_teaser_en_us.jpg." A Diablo 3 expansion perhaps? Back in November, Blizzard CEO Mike Morhaime did say that an expansion for the popular RPG is being "planned," but offered no official details. Adding to that rumors is Blizzard's invitations to a Gamescom event where the company will make a "special announcement that's sure to capture the attention of the Heavens, Burning Hells, and all the shadowed places that lie between."

The event will take place on August 21, the first day of Gamescom, at 11:30am local time. Gamescom takes place August 21-25 in Cologne, Germany.