MMO combined with tabletop RPG

Neojac

We are developing a mmo game called Islands Of War and one of the things we will have is the Builders Club where players will be able to build their own islands and story line. Be able to place NPC, Mob , ext in real time. These builders will then have the option to invite people to their islands to play these quests. With this we are thinking of providing the tools for the builders to create fully functional desktop rpg story's where the GM can spawn a nps for instance, and take control of him to interact with the group of players he has invited to play his island. Would this be a viable idea to pursue. Any comments?