Binding issues

OK.  I'm trying to do a little binding here and I'm running into a few issues.  I have a list of objects that all implement an interface.  That interface specifies a couple of things.  First a String property named VisualizationName and then a UIElement property called PreviewControl:
 
public interface IVisualization
{ 
string VisualizationName
{
            get;
}

UIElement PreviewControl
{
            get;
}
} 
Simple so far right.  Now I have a listbox that is to display these items.  It is as follows:
<ListBox x:Name="viewsListBox"  SelectionChanged="viewsListBox_SelectionChanged">
    <ListBox.ItemTemplate>
        <DataTemplate>
&n ...