During the Blizzard Press Conference at Gamescom in Cologne Germany, Blizzard has confirmed that "Reaper of Souls" will be the first expansion to Diablo 3.
Reaper will introduce the Crusader class which brings the total of playable classes to six, an increased level cap to 70, a whole new act to play through and a new big bad Malthael. (Why is called Diablo, then? /snark)
According to Blizzard, Malthael is the fallen angel of wisdom, now an angel of death. He's is working to reap both demons and humans alike and end them all. Blizzard is also working to offer different options to Diablo 3's endgame. This includes loot runs and upgrades to the game's paragon system, plus much more.
Blizzard also plans to revamp the loot system in the game. Loot 2.0, as Blizzard calls it, will have more drops for the class you are playing at the time. Loot runs are also being added to the game: 20 minute random dungeons with a random boss for quick loot and coop adventures.
Stay tuned to this post for more details as we scrounge them up!