Louis Gray has 10 excellent suggestions for improvements to the usability of Google Reader — which I think can be and should be in all online RSS feed readers.
1. “More Like This” Suggestions
A section that shows similar feeds to the subscribed ones.
2. Eliminate Duplicate Feed Items
The ability to determine if a story has already been [...]

With the mainstream use of CSS (custom style sheets) comes the question of whether or not you should underline your hyperlinks, now that you have a way to do so or not do so very easily.
Of course, readability experts suggest that underlined text is more difficult to read (as is itallics and bold), so if [...]