It took a while, but a new themes engine has been created. That should make it much easier for me to create new tilesets for DunGen, shaving the time needed by several weeks.
The first one available is the Ice Temple, as pictured above. Dungeon Architects will have access to download the full tileset soon, as I still need to add a few items that the generator doesn't use.
I hope you enjoy the new feature; there are some new and varied themes already in my to-do list but if you have any suggestions I'd love hear them!
Nick.