Anons Now Allowed To Comment
As I mentioned in a comment below, I didn't realize I'd set comments up for registered users only back when I went to comment moderation. I knew comments had dropped off but hadn't noticed there's been no anonymous comments for some time.
Taking a look at the admin page for comments, I see I did, indeed, allow only registered users to comment. For the life of me, I don't remember doing that. I just remember enabling moderation.
Anyway, against my better judgment, I've set it now so anons can make comments. Comments are still moderated, though. I say against my better judgment if only because I kind of like the way it's been so peaceful and quiet around here lately.