Hey!
I was thinking about doing something along these lines awhile back. (A generic AI type engine for irrlicht).
Anyways, I'm gonna try and read over the source code today or tomorrow, and see if there is anything I can add.
I will look into trying to make an algorithmic pathnode creator (i.e. you pass in a quake level to the function and it returns a waypoint map.)
Also, I have looked over opensteer and some other basic steering behavior stuff and I will see if I can implement these behaviors somehow into the IrrAI.
Another thing that might be useful is to have a sort of entity interface wrapper.
I.E.
Where the user must implement the movement functions themselves (forward, back, etc) but the AI engine calls them, so that the AI engine has no need to know of the internals of the game engine or whatnot.
Another thing that this allows, is that if the AI engine has a copy of the level mesh, along with the waypoint / visibility map, you can have the IrrAIEntity wrapper register itself with the AI engine, so that you could put tags on the entities, so that the AI would be able to recognize them, like health powerups, squadmates or whatnot.
I also plan on useing it somewhat for a project I'm working on
Anyways, hop on the IRC sometime JP.