Much like the four long years of development behind it, Diablo 3 players have been long waiting to see the addition of a Team Deathmatch mode since Blizzard promised its arrival. However, according to Blizzard's lead designer Jay Wilson, the mode "isn't yet where we want it to be."
Apparently Blizzard wants more to the mode than just an all out brawl. Said Wilson over at battle.net, "Simply fighting each other with no other objectives or choices to make gets old relatively quickly. We've brought a lot of people in to try out Team Deathmatch and, while some found it entertaining, most of our testers didn't feel like it was something they'd want to do beyond a few hours."
Additionaly, Wilson points to the issue of class balance. "Like Diablo II, Diablo III was designed to be a PvE-first kind of game, where we never compromised on player abilities in the name of future PvP balance."
As such, Blizzard is taking Team Deatchmatch "back to the drawing board," and a replacement is under way.
Wilson adds Blizzard will add "Dueling" soon, due to solo fighter fan demand. "First and foremost, if our original goal was to support dueling, then we're not achieving that goal very well if we don't actually give players a way to duel in-game," he wrote. Dueling will arrive via patch 1.0.7 sometime next year.
Not much else has been released by Blizzard about 1.0.7, only that it's "planned to be a larger patch than 1.0.6, and will contain much more than just bug fixes."
Wilson promised Blizzard looks forward "to posting more about dueling in the next few days."