I’m not seeing a new software update on Windows Phone this week for some reason. (Germany?) But I did see one previously. This is what it looked like on the phone:
The update I got was for testing purposes only. That is, it didn’t add any new features but was rather designed to just test the updating functionality. The OS version number didn’t increment, etc.
I’m not sure if this applies to Microsoft-delivered software updates, but there is a 20 MB limit for over-the-air updates for application developers. Anything bigger than that has to go through the Zune PC software instead. Regardless of what the actual limit is for Microsoft’s updates, there is some dividing line between OTA updates and those that require you to connect via USB. This particular update exceeded that limit.