A couple of times today I've noticed the Facebook mini-site everybody loves is showing all Stack Overflow questions, not just Facebook related questions. This occurs on the new question list. Here are a couple of screenshots of examples (it happened to be both logged in and not logged in):
Sigh... Me again. I've been deploying some experimental code changes to the way our tags are handled... I guess something in sub-sites wasn't applying the sub-site completely. I've switched back to the stable version for now.