The river of news is via a steady feed set (you can add a blog and the editors will see if it is fit for the portal).
People can give posts a thumbs up or down, basically ratings, like Digg.
View most popular rated posts (thumbs up), or most unpopular posts (thumbs down).
View most recent posts, or least recent posts.
Grab the spliced feed river of news, or better still the Reading List (Download Master OPML) if you want to read posts by feed.
NOTE: BlogBridge and FeedBlitz users can subscribe to the OPML URL itself, so any new feeds added/deleted will be reflected…ie. don’t have to reload the static OPML everytime to be sure you have the current version.
If you are not into subscribing, just view it publicly at Optimal…check it out.