"Early this morning we were alerted by our customers that there was a widespread issue affecting our 2006 model Zune 30GB devices (a large number of which are still actively being used). The technical team jumped on the problem immediately and isolated the issue: a bug in the internal clock driver related to the way the device handles a leap year. The issue should be resolved over the next 24 hours as the time change moves to January 1, 2009. We expect the internal clock on the Zune 30GB devices will automatically reset tomorrow (noon, GMT). By tomorrow you should allow the battery to fully run out of power before the unit can restart successfully then simply ensure that your device is recharged, then turn it back on. If you're a Zune Pass subscriber, you may need to sync your device with your PC to refresh the rights to the subscription content you have downloaded to your device."
There you have it, straight from the official support thread on this problem. So for those of you who were about to take screwdrivers to your Zune and open them up, just wait until tomorrow and it should start working again. This confirms that it was in fact caused by this year being a leap year, and thus having 366 days. I'm shocked and disappointed that Microsoft allowed this bug to go un-checked - they have some of the longest and most grueling test cycles in the industry for their software, so I'm stunned that the Zune team allowed this to happen. The Zune is struggling enough as it is, this is a black eye it really didn't need. We'll discuss that issue in a couple of days...I have some thoughts about it.