Update: Jim wrote in to let us know that someone at Microsoft has apparently finally woken up and checked their e-mail (yikes, imagine that inbox). The official Zune site now has a message stating that Redmond's best are aware of the problem and "are working to correct it." We'll keep you posted.
Update 2: Major Nelson just tweeted that anyone with an issue "should be good to go." Exactly what that means, however, remains to be seen, as there's still no word of an official fix on the Zune site.
Update 3: Oops, sorry for getting your hopes up. Seems the Major was wrong and is now indicating the team of Zune developers is working like mad to figure it out. Somebody had better order in lunch for those guys -- it's going to be a long day.
[Thanks to everyone who sent this in]