Not "meme" but something that is more specifically limited to stories reported in mass media. Examples have varied in real-world importance from gigantic world-changing disasters or triumphs of good over evil down to pointless "oddly enough," but there's some characteristic quality that I can't identify here that makes me say "well, I'll be seeing this shit on my friends page for a while now" when I see it.
My guess at the moment is that certain stories flick a switch that makes us say "I must tell others about this and talk about it" that is independent of any judgment about the importance of the story or the likelihood that you'll be the first to tell anyone about it. I bet if they ever localize this thing in the brain it'll be in the same nerve bundle as whatever makes us talk about the weather.
The item that sparked this line of thought was of course today's death of a minor celebrity, which is almost entirely at the trivial end of the scale, only escaping the "oddly enough" silliness because it involves one actual death of a human.