No clue what happened, but our hosting company migrated us because the old hostmachine went bad overnight.
Their most recent uncorrupted backup was May 14th, so they got us that far, and then I was able to restore a backup I had from late Monday night.
I'd like to thank everyone for their patience, and apologize for the inconvenience - I see that we are missing a few replies here in the forum, the newsletter subscribers got a newsletter they saw last week, and several folks got "new forum post" subscription emails that they had already received last week.