I'm maintaining cautiously optimistic about a Friday delivery. I looked at my Galaxy Nexus shipping notification and it came at 2:47 in the morning, so its possible today's Nexus 4's have shipped and emails will batch out. :)
I've seen some in the forums posting that UPS has alerted them that they have deliveries tomorrow. I think Google's email system is totally borked. They never sent emails that the Nexus was for sale, and shipping emails seem to be coming late.