From what I have been reading online, the Viera Cast product is now obsolete anyway, since 2011, and Panasonic have replaced it with Viera Connect, which features a whole lot more apps, an app marketplace, and is open to third-party developers. My DMR-XW390 would be a whole lot more useful with Viera Connect software instead of the older Viera Cast. Why is Panasonic still bundling their obsolete software in their new devices?
I notice that the DMR-XW390 has the ability to update its firmware through the Internet. I have configured this option and left the Internet cable connected and the device turned to standby at the appointed time (3:00am by default). However, the software version listed on the System Information screen before and after the "update" remained the same. It shows as software version 1.00 both before and after I supposedly updated it. I have contacted Panasonic NZ for support on this, but they didn't even know what the latest software version is supposed to be (they'll ring me back).