EtreFeed integrates RSS feeds with new user notifications in OS X 10.8 Mountain Lion. Just add RSS feeds for all of your favorite web sites into EtreFeed and you will be notified whenever a new story is posted. You can double-click the notification to go right to the story, ignore it, or look at it later in EtreFeed.
EtreFeed isn't like other RSS readers. It is not designed to be yet another application demanding time from you. EtreFeed is designed to save you time. EtreFeed is an RSS reader for people with better things to do.
Note: The demo version is currently at 1.2.1. The version available for purchase on the Mac App Store is 1.4.2.