Just a quick thought: now that Bloglines is closing, and Google Reader is the winner in the RSS reader market, perhaps it’s a good time to create a new type of reader, perhaps focused on people (and faces). With a UI in between FB/Twitter and Bloglines/Google Reader. Something like this?
Peter Van Dijck 
spot on.
Feed readers should be simple and straightforward, stress free, not an ever ending cumulation of unread posts. Things to be taken into account:
1. a visual association with the source
2. a vertical and constant stream of information (like twitter). no categories. if you haven’t read your feeds in xx days they are automatically erased.
3. a visually appealing design
4. simple. there should be only two actions: a ‘keep’ button to read stuff later and an ’email’ button to share stuff. and that’s it.
we’ve been working on a reader that somehow picks up these things, we’ve called it planetaki (www.planetaki.com). Here’s a preview of mine for example: http://www.planetaki.com/lendo If you get a chance to check it out, it’d be great to hear what you think.