Google Reader could add a lot of features from Gmail that would improve the way it organizes information.
A filtering mechanism would allow you to automatically star, share, email, label or mark as read the posts that match a certain pattern. For example, you could receive an email for each post that contains GDrive in the title or automatically label as Apple all the posts that contain one of the keywords: iPod, iPhone, Mac, iMac, iTunes, Steve Jobs etc.
Conversations are a great way to group related messages and could also be used to cluster posts based on their topic and the backlinks. You'd see the chronology of the articles and read all the posts about a certain subject successively.
Colored labels should make it easier to identify related conversations, especially if you read them in a combined view.
To reply to a post, select a fragment and send it to Google Notebook, Blogger or another blogging platform. To forward a post, send it as an email, an instant message in Gmail Chat.
Create an inbox-like view that doesn't include all the incoming posts: only those that weren't automatically classified and archived using filters.
Mute annoying conversations: a post gets a lot of replies, but you don't think it's interesting. A special option would automatically archive all the future posts from that thread.
If you don't like the web interface, an API should allow those who develop desktop feed readers to implement synchronization with Google Reader.