Another indication of Chrome extensions?

Giving Chrome a real workout…running the dev channel version at the moment, at least until it implodes on me.  I noticed this on that “visited sites” tab.  The link takes you here.  (I was hoping to see some humongous extension gallery that had just launched, but no.)  Maybe this means they are right around the corner, eh?  (Update: that little blurb is now missing.  Definite conspiracy action here.)