A WebmasterWorld thread reports that many publishers have received an email recently from Google notifying them that they have been paid. Some, initially, felt the email was spam or a phishing attempt, but after closer review, the emails do appear to be coming from Google.
I personally did not receive such an email. Some reported the email being sent to their junk filter. Some reported not receiving it at all, like me. Some felt it was spam, like I said above. I do not have a copy of this email to share with you.
Google did not yet chime in about this email, but from what I am seeing, it does seem to be a new feature. It is nice that Google lets publishers know, via email, when they were paid - but they can give publishers a way to opt out of such notifications.
Forum discussion at WebmasterWorld.