I’ve written a kind of basic Lightwave LWO and LWS importer for Xith3d, but it’s with many restrictions. Basically it just fits the needs for my current hobby project, so I’m afraid it’s not very useful to others.
It’s not related to the Java3d LWS/LWO importer because when I’ve started writing the importer I’ve been using JOGL. So in the end I’ve re-invented the wheel I’m afraid, but with my wheel being rather a kind of triangle. 
LWO import:
° It doesn’t use the nice Xith3d Loader interface.
° It skips many of LWO’s more complex features (it’s a basic importer).
LWS import:
° Currently no support for animations, but will do this soon.
° Currently no support for bones, but when Xith3d supports it, I’ll add LW bone import.
Parsing exotic formats like the binary and hacked LWO file format isn’t my strength, I’m afraid. The vastly undocumentated LWS text file format isn’t a pleasure either.
I’d love to see a real and solid Lightwave LWS and LWO importer for Xith3d. So if someone liked to do this or ported the Java3d LWO/LWS importer to Xith3d this would be nice. I’d help where possible. Still there would be many things to add: new LW 7.5 features for example, etc. Soon there will be LW 8.0 and I’m going to add some of its features.