Another riff on the theme of object-based views is that of view combinators. This might seem weird, but bear with me:

# views.py
comments = ModelResource(name='comments', model=Comment)  
videos = ModelResource(name='videos', model=Video)  
video_comments = videos.sub_resource(comments)

# urls.py
urlpatterns = patterns('',  
    (r'^videos/', include(videos.urls + video_comments.urls)),
)

The sub_resource() method on ModelResource takes both resources and creates a URL and object hierarchy. It would be capable of inspecting the models and discovering the relationship (whether that was a foreign key, generic FK or M2M), then generating sub-URLs like /videos/123/comments/456/.

Just a thought.