In recent months, more comment spam has been getting through. To deal with it, I’ve had to tighten up and hold more comments for moderation, which means some comments may be delayed in appearing until I manually approve them. Also, I’ve noticed that WordPress seems to have similarly tightened their settings for auto-identifying spam that doesn’t even reach the moderation queue, and so those comments will be similarly delayed until I check the Spam folder and manually mark them as not-spam.
Unfortunately, this means your comment may be delayed in appearing, usually by a few hours but sometimes up to one business day (I have a day job). My policy is to approve all comments whether they agree with me or not, except only for spam and obscene or content-free flames, so if you leave a legitimate comment but don’t see it appear within a day or so, feel free to email me.