Hey Diablo 3 will be takin place during a war between heaven and hell, because the worldstone broke the barries between the worlds. I really have no idea about bosses or playable characters. However, check this out and know that I'm not makin this stuff up! Blizzard is lookin for a new game designer to work on an "unnanounced PC game."
http://www.gamingsteve.com/archives/..._diablo_ii.php http://www.gamespot.com/news/6130138.html