Blizzard Entertainment are hosting a press conference on the first day (trade only) of Gamescom in Cologne. Up until now we had no solid information of what the focus might be for the presser, but the official invite invite includes the following phrase:
"You are invited to join Blizzard Entertainment, on the first day of gamescom, to find out what lies ahead for the world of Sanctuary."
Sounds like we could be getting a first look at the inevitable expansion of Diablo III...