(Click image to enlarge)
I'm not sure whether to call this a social network, an aggregator, or just a cool tool to let you see what others are saying before you post?
I originally thought it was Blogger-specific when it was first announced and held off trying it. It's not. You can add any RSS feed to the list, and the step-by-step interface makes it simple. (Very simple). You could, if you wanted, add your entire reader list (although I think for most that would be impractical).
This blog is produced in Blogger so I see that page each time I update. I can think of a lot of possibilities utilizing this moving forward.
To try it out, all you need is a Blogger profile and simply go to the main page or draft.blogger.com.