To be honest, I could care less about modding D3. My opinion is that no matter what D3 plays like, it's not going to satisfy. Further, it's not like a single person who developed D2 even works at Blizzard anymore (unless you count the guy voicing Cain). It's a sequel, but not spiritually.
If I was to get into modding 3D games, I would be modding for the Fallout series.