I don't see how you could split the admin from Model classes since it's essentially a visual representation of the Model API. You could give the admin page custom Forms that aren't ModelForms and yes, the admin could make that easier (custom admin forms are a bit annoying to do currently), but then all you'd get from the admin is a navigation bar and breadcrumbs (and maybe search/filtering if you reimplemented the query builder). Might as well just make your own admin pages at that point.