Diablo III as an MMO game? That was apparently the original plan at Blizzard when the team first started developing the game. In a new article at Games On Net, former Blizzard team member Max Schaefer, now the co-founder of Runic Games, is quoted as saying, "When I was working at Blizzard a million years ago we were working on Diablo 3 and it was an MMO. We were going to do the Diablo version of World of Warcraft."
The plan obviously changed and Diablo III was finally launched in May, after several years in development, in its current form as a action-RPG single player game and a free online multiplayer game, although with some persistent elements as well as an in-game auction feature. Schaefer left Blizzard and went on to help form Runic Games. That team released their own action-RPG game, Torchlight, in 2009. The developer is close to launching the long awaited sequel, Torchlight II.
Apparently, pre-orders for Torchlight II have actually benefited from the launch of Diablo III. Schafer says in the new article that Torchlight II sales on Steam went up by 40 percent following the release of Diablo III and have stayed at that level. Torchlight II will add online multiplayer, something that was lacking in the first game's release.
Source: Games On Net