NetNewsWire Lite is a free RSS reader for OS X, done in Cocoa. I've been playing around with it for an hour or so, and it seems pretty darn sweet. I've been unable to tell whether or not it will regularly (say, on the hour) check your subscriptions for new content, though.

Radio has hooked me on reading RSS feeds, but the HTML interface it presents is pretty awful. NNW seems a lot closer to what I'm looking for.  3:53:49 PM  (comments [])