Right now you can't change a container's layout once you've instantiated it. I think it would be very helpful to be able to do this. Is anyone else interested in this ability?
This would be especially helpful with mobile sites, where you often need to rearrange things depending on the screen size and orientation.
I know you can create a new container with a different layout, and move the old one's items into it, which is what I've been doing. But this requires an extra container layer (if you want a component to be able to change its own layout), so it's not ideal.