According to a recent update from the Diablo III team at Blizzard, PvP will not be included in the initial release of the game. While Blizzard puts Diablo III’s release date in terms of “days”, the developer also believes that the PvP portion of the game “aren’t living up to our standards”.
While we work on making sure PvP lives up to its full potential, we hope you’ll find some consolation in the fact that soon, you’ll be having a blast leveling characters, finding items, learning the classes, and perfecting builds…and that when the Arenas do arrive, you’ll be all the better prepared for battle.
Blizzard intends to patch PvP into the game after launch however. When they do, Diablo III PVP will include “multiple Arena maps with themed locations and layouts, PvP-centric achievements, and a matchmaking system.”
Expect an extremely polished campaign and cooperative experience at launch, which is still at an unknown date at this point.