ECU updates that are normally done by your dealer could in theory be done OTA like that. So, 10 minutes of 'down time' instead of a trip to the dealer and an hour+ of down time.
Seems like something that you'd want triggered while you plug in/refuel; when your car obviously isn't going anywhere for a few minutes. And using tricks like Chrome OS has (a/b partitions for current/update) could shove the actual downtime to not much longer than a reboot takes (hopefully seconds)
