Right now, tons of Zune 30s are dying around the clock for no apparent reason.
Since the beginning of December 31st, most 30 GB Zunes that has been reset or turned off failed to boot up again. The crisis has been duped by Zune owners as "Y2k9", but it doesn't seem to be related to the year turn over.
Microsoft's support is still on vacation, but the company issued the following official statement: "We are aware that customers with the Zune 30GB are experiencing issues with their Zune device. We are actively working now to isolate the issue and develop a solution to address it. We will keep customers informed on next steps via the support page on zune.net."