Kevin Caccamo
Rear Admiral
I just updated the exporter script today. It now shows you the associated texture number of each texture, as well as some other under-the-hood improvements.
I just shared the OBJ2WCP Java-code, as it was not available on GitHub before (only as .zip from your website).You'll need to re-download and re-install Wing Blender 1.5 to apply the update.
The exporter handles smooth groups as you'd expect. If you use the exported mesh ingame, the smooth groups should be intact. You can mix smooth and flat faces on the same mesh.
The importer doesn't detect smooth/flat faces right now, unfortunately. You'll have to re-do the smoothing yourself.