Age of Conan has a amazing non RTS siege system.
As example you can build city's and even a fortress in this game with your clan. But thats not what i'm trying to propose.
Looking at the end of that video you see about 2 walls and a keep as he mentions.
That's what i picture DoF looking like, a main wall a second wall and your keep.
Any developers here to back this up, or tell us what you think about that video and how it relates to DoF in any way.