What is a good model for IoC + Ribbon?

We are using an IoC model for our WPF tools, and are quite happy with how it's all working out.

Now we want to add a ribbon to a new tool we're creating, and I'm running into some design problems. I'm looking for guidance on how plugins in our tool can expose their interfaces to the main window's ribbon.

We want to be able to continue letting a designer use Blend to lay out and tweak the ribbon elements based on production team feedback. With all plugins' interface components exposed at once if possibl开发者_如何学Goe.

I'm looking for some guidance on this before I start button-mashing. If it were a simple hierarchical menu system, then that would be pretty straightforward. But the ribbon permits galleries and listboxes and all kinds of interesting context-sensitive UI.