I have committed all of my latest changes to the ModelLoader API. All of the loaders (except for Cal3D and COLLADA, which will follow in the next days) have been ported to the new architecture, where more code resides in JAGaToo and factory interfaces are used to push the loaded data to Xith3D.
Now you don't need to use a specific loader for each model format. It is done the exact same way for all formats.
This is, how you load a model now:
Model model = ModelLoader.getInstance().loadModel( modelResource );
I have also fixed CelShading (if anyone cares).