I've been a subscriber at Google, Facebook & More Search – Social News | WebProNews for quite a while now. I really recommend all of you to subscribe to their newsletter, because they're giving awesome information about for example Google and its algorythm changes way before they changes are implemented. Meaning you can prepare niche sites or SEO activities in a timely manner to keep up with google.
I just thought this will be a great source for all of you, especially becaue so many here are into SEO.
You won't be disappointed.
This also the organization who researhed the traffic from Twitter and Facebook (among other social networks) with astounding results.
I quote: "Traffic from Twitter and Facebook SUCKS !"
Andre