Newsvine is a clever and unique website that allows you to act almost as a journalist or reporter. I have recently signed up for the site and am enjoying it very much. The site gives you your own personal column so that you may write articles, as well as post (seed) articles from other sources. It works in a Digg-like fashion, where users can vote on articles or "seeds," and the best will be the most likely to be featured and read.
In addition to this, you can also make money with any advertisements that are clicked on your column. So you might be able to make a few bucks on the site if you are really good at writing. I also really enjoy the groups feature, which allow you to join a group and have people of similar interests post and comment on news items that might be interesting to them.
To sum it all up:
I don't believe I have seen anything like Newsvine before. I know one thing is for sure though, this site is only going to get bigger and better with time. It is destined for success if properly maintained. If you like news where the users are the people who discover the content to share with everyone, and also create the content themselves, then this site certainly could appeal to you!