1. If the media object is the primary content of the entry (which seems to be the main use case for RSS 2.0's <enclosure>), shouldn't it be delivered using some form of the <content> element?
2. Without multiple rel="enclosure", how does support and differentiate between media objects that are essentially the same resource but different formats, where the difference may not (easily) be expressed using mime types? Example:
3. I don't think this Pace is the right place for listing what should go in the <link> registry - separation of concerns and all that
4. What do we call an inline (i.e. base64 encoded content) media object - an attachment?