How about a internal scripting language (Something called ZC script?) with function based internal hooks?
This would allow people to code AI scripts for monsters, custom triggers for events, custom teleportation triggers, and if access from this was added for the main the scheduler so the language could queue, de-queue, find, search for, and clear events it would allow timed events and take care of a number of feature requests. Heck you could even make cut screens and cinematic movie-like stuff happen with the right functions.
Better yet people would have the ability to add ideas themselves without bugging the dev team. 😃