While following the current news story about the hostages in a mall in Kenya, I noticed this report from CBS. It is interesting because of the way social media is included in the reporting of the situation. The tweets are shown as quotes.
I have not seem much of this kind of reporting from libraries about their collections, although the British Library has used used social media as part of their story telling. You can see recent tweets on their home page, and exhibition pages often have an embedded feed of recent tweets using the exhibition hashtag.