Alexa is that a traffic and popularity scale for Site owners as well as visitors. We regularly check Alexa for our site’s rank, performance etc. but because of the Alexa Toolbar (a toolbar created for Firefox browser), Alexa can check the popularity of a particular URL and then share that with us. Yes, It is more or less real time. I am talking about the “What’s Hot” section available on Alexa.
Alexa’s What’s Hot Section or (Hot URLs) is a real time up to date section where you can find the breaking news, latest buzz etc. on Internet. Alexa updates this section on an interval of 5 minutes. So after each 5 minute, this section will have updated news or links. I agree with you hat Twitter and Facebook are much better source of breaking news and latest buzz. But you can also add Alexa in that particular sector as it shows the links in a bit organized manner.
You can select a particular hot or trending topics for example “Avatar” and find the popular sources for that.
Related: Alexa Traffic Page Complete Guide