The only medieval themed mod that WG or I will be working on any time soon is the next installment of WGR2. Since WG hasn't had time for mapping lately, I'm thinking about putting together some kind of WGR2 release to fill in the gap.
Since I haven't done anything for agees, (And I dont know when I will) if you want to release a update with the new code and player thats ok, just none of the maps. I have to admit though that some of the texture replacements look worse to me.
I can swap in the old maps, but I don't even remember if I have updated ones since the release. My idea was to try to get Spiker to finish his map, then release a new version with that, the new character, and some other code updates.
I have also considered making a map conversion feature, where if you open a regular Duke map it will convert the textures, monsters, items, etc. to WGR2. That would be a lot of work, though, and I'm not sure if the result would be worth it. The results would be weird, and I would need a lot of new sprites (e.g. medieval replacements for the movie posters and shit). The idea is that Duke tries to return home and he gets mixed up in some kind of alternate universe (not officially part of the story, but a good explanation of why there would be weird maps like that).