> And isn't showing the content of the RSS feed "fair use" anyhow?

Fair use and copyright are 'artificial' legal constructs, so if they were defined in an 'arbitrary' way to begin with, they can be redefined to add or remove provisions. These online publishing laws could tweak those provisions.

Also: when an RSS/Atom feed is published, it is still copyrighted, and the terms and conditions would/could perhaps be defined what "fair use" is by copyright holder (maybe?).