Well it's about time. As a veteran of Diablo III, I've been waiting for this for a while. At Gamescom, Blizzard just announced Diablo III: Reaper of Souls
The Angel of Death, Malthael, has taken the black soulstone, which houses Diablo. The game will take place in the city of Westmarch and includes a new class called the Crusader. The Crusader is described as a "war machine made human" and is said to be similar to the Paladin class of old.
New monsters and new angels will be in the expansion pack and, of course, new features. Loot has been decreased but chances of getting an item for your class has increased. Also, there's now a Mystic that will let you re-roll item affixes. Oh, and now there is no Paragon cap so you can Paragon to your heart's content. And if you guys want to loot, there are now loot runs with randomized dungeons and monsters that are made to do quick looting.
No release date was announced unfortunately.