Fortifications and Sieges

One thing I'd like to see more of in Elemental is sieging / storming fortifications and cities.  What I mean by this is walls that you have to break down (or scale), defensive structures like ballistaes, mage towers, that kind of thing.  I really liked those aspects in Age of Wonders.

I know the tactical battles in this are intended to be smaller that something you'd see in Total War, but I'd love to see assaulting heavily fortified cities / forts a real challenge.