However, I agree 100% that the playable races' histories and cultures within the game are extremely well thought out and it does make everything more fun to play. But I wouldn't exactly call them different from most fantasy races.
And Rune, your race is very cool. I love what you've got going with them and think that the other humanoid races would benefit from being as unique and detailed.
Now, I haven't created the Dragons yet, partially because I want to give them a more complex culture than just being Big Bad Monsters. And I'm not doing so well with getting my thoughts together on that.
But the way I see it we have at least a few options for adding races and cultures into the world. Two ideas I just thought of:
One thing we can do is, once our races are created outline different subspecies that the will evolve into.
We could also try to have everyone come up with at least an idea for another humanoid race & their major culture(s).