They don't show it on the status dashboard at https://status.aws.amazon.com/ (at least at the time I originally posted this comment).

But if you go to your personal health dashboard (https://phd.aws.amazon.com/phd/home#/dashboard/open-issues) they report an S3 operational issue event there.

Edit: Mine is reporting region us-east-1

Edit 2: And now the event disappeared from my personal health dashboard too. But we are still experiencing issues. WTH.