Polygon reports that the special invitation they received stated "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." While this may just be more information about the upcoming console ports for Diablo 3, one has to wonder if perhaps this is something more -- perhaps the first mention of a Diablo 3 expansion? It's certainly about time we heard of such things, but of course, we won't really know for certain what the special announcement is all about until Gamescom opens in August.
Be sure to head over to Polygon for more details regarding the upcoming press conference. For more information on Blizzard's presence at Gamescom, be sure to check out their official dedicated website for the event. And if you're planning on attending, you still have a little time to sign up for the Blizzard costume contest as well!