[KaVir]

I think in many cases it's good writing and interesting characters that make a novel what it is - things that don't really carry over well to a mud. Many novels also seem to have a relatively small bestiary, which could prove quite limiting for a mud that emphasises combat.

The Malazan Book of the Fallen series you mentioned is interesting in that (at least IMO) the stories seem to focus more on the history of world than on the characters, and there's clearly plenty of room for adding powerful and important individuals (rather than a typical fantasy novel where the villain is the biggest badest wizard in the world, and the hero is the "Chosen One" prophecised to defeat them). My main concern with using the Malazan setting would be that although there are lots of races, there don't seem to be many non-humanoid monsters.

Compare that with a D&D setting such as Forgotten Realms or Eberron, where the players can go out and fight monsters in a huge variety of shapes and sizes. From the perspective of creating a combat-oriented mud (which admittedly isn't a goal for all muds but which is important to me personally), I think such variety can add a great deal of value to the game.