I've been slowly developing my own fantasy world, and my most recent development was a good web, which I shared the problems, basics, and results of in the forums. As such, I now know the shape and what lives there.
I have five namesless, faceless, genderless divided whom created this world for unknown reasons. The technology that would be developed by humans doesn't rationally fit directly into a world of Anthros and magic.
So, despite the world becoming more believable, new problems are arrising, too.
Questions on tools, weapons, buildings, and defenses are now a major issue. Looking over the races/creatures, human concepts, designs, and thinking no longer apply.