Jayson Napolitano of Destructoid has a fantastic article up about the Diablo III sound team.
Diablo III’s Sound Supervisor is Joseph Lawrence. I’ll ask him to identify the key people on his team, however I think it should be noted that the entire Blizzard sound department has been involved at one point or another on the project. Diablo III contains the most dialogue, sound effects and music of any single-box release in the company’s history. It takes a village (or tribe, in Blizzard-lingo)! Other composers on the score include Derek Duke, Glenn Stafford, Joseph Lawrence, Neal Acree, Laurence Juber and Edo Guidotti.
The meat of the sound design comes about halfway through the article, but all of it is a worthy read. Go check it out now!