In addition to the 5th class, Blizzard also announced some details surrounding the PVP system! There will be an arena based PVP system, where players will be transported to a separate, specific arena type area. Battles will be team based, up to 4v4. In a nod to Diablo 2 PVP, you will be able to collect ears from your fallen opponents! The ranking system will be progression based, not skill based. Rewards to include achievements, titles, and other vanity items. It was also mentioned that there will be a robust and easy to use matchmaking system.
More info. to come as it becomes available!