The navigation meshes are basically an advanced, but more complex
approach for pathfinding / other search algorythms.

I rather suggest to implement a better line-graph-editor.
In the end the graphs are just infromation, wich needs
to be used in a thoughfull way by the user.
(And only few users actually manage to put up a working pathfinding)

What is more important is to provide an easy to implement
pathfinding function for inexperianced users (based on
line-graphs). Could be a templeates feature then.