There are a plenty of “buzz” sites (e.g., Yahoo! Buzz, Digg) and newspapers have had community integrated for some time. But the HuffingtonPost is using Facebook Connect for a “social news” site that will broadcast what you’re reading to Facebook news feeds and expose Facebook connections on the HuffingtonPost site:
This appears to take Digg a step further.
I wouldn’t necessarily want everything that I’m reading to show up in my FB news feeds, but the site will be worth studying to see whether a similar model should be adopted by newspapers more broadly.
AllThingsD has more discussion.