MTV Multiplayer reports:
"Although many "Diablo" fans have expressed fondness for the Necromancer from "Diablo II," lead "Diablo III" designer Jay Wilson confirmed to MTV Multiplayer that the character class will not appear in the initial release of the game.
When the team was choosing which classes to include in the long-awaited sequel for Blizzard's best-selling action-RPG series, they decided to create a brand-new one - the Witch Doctor. And with only five classes in the game, "Diablo III" just didn't have room for two curse-dealing, pet-wielding classes.
Here's Blizzard's explanation for why the Witch Doctor replaced the Necromancer..."