I am making an application that is a dashboard/widget host.
I am using MEF to load the plugins and I have a ui Concept Idea like this:

http://i42.tinypic.com/scb6nd.png

1. Is this a good design choice?
   
2. How would I implement the Navigation?
3. Is there any Design Patter you would reccomend for this?

Note: My contract interface is this.

public interface IDashboardPlugin
{
   public string Name{get;}
   public string Description{get;}
   public string Author{get;}
   public UIElement UI{get;}
}