Like, for example, the fact that a version of Diablo 2 was considered for the Game Boy Color and/or the Game Boy Advance. Following the release of the popular sequel, Blizzard North considered a single-player handheld game with the working (and adorable) title of Diablo Junior, which would have three separate cartridges on offer, each featuring a different class of hero. The game was never made, mostly due to the high costs of mobile development at that time.
Craddock says Blizzard North also considered a second expansion for Diablo 2, which would have come out after Lord of Destruction. That expansion would have focused on multiplayer features, and set up customizable guild housing and banks. In the end, however, that expansion was also scuttled, and Blizzard North got to work on the long project that would become Diablo 3.