A handy chart of search activity on “blogs” and “social media”:
At first glance, Google Trends appear to indicate blogging is on the way out. Ye olde webbe logge is so 2004, after all.
But I don’t think a wholesale abandonment of blogging is underway. Instead, prior to 2008 people used blogging software as a crude social network. Once facebook arrived with a better product for that sort of thing some demographics no longer blogged, leaving the blogosphere to people whose activities were a better match to the tools.
In any case, Facebook’s dominance is now absolute: