In my view
<%= Html.DropDownListFor( x => x.Countries[ i ], Model.CountryList )%>
in my controller
public int[ ] C
This is a bit of a hack, and JavaScript reliant but it worked very well for me.
You'll need to know the client IDs that will be produced by the fields (usually these can be worked out manually but for safety you may want to use something like a FieldIDFor method.
You just need to set the values based on the model, in jQuery's $(document).ready: