I always had some sort of navmesh'ing at some place on my never ending todo-list and also had an eye on the Recast project, so, I am very keen on your project.

Your demo could be even cooler if you would let the user select a MDL and click with the right button to place a guard and with the left button to let the guard walk to the clicked position. This could teach people how to invoke navigation-starts and how to determine the nearest position on a nav mesh from a 3d point in space (or if it is not on the nav mesh).

What I would find interesting is how to save a navmesh and re-use the saved file and if it could be loaded from a buffer (e.g. so that it can be contained in a WRS).

If you could provide a navmesh generation process that takes a wmb with the data of static meshes, models and flags like passable or invisible or so as source, this could become quiet handy!