Follow Rapid Repair's guide to taking your Zune apart to step 4, so you have access to the hard drive and the battery. Disconnect BOTH the battery and hard drive, and then plug 'em back in. This apparently resets the Zune's internal clock, which brings it back to life. Put it back together, and it should be 100 percent again. (Assuming you don't screw it up.)
The risk here is that we're not sure how attempting this DIY fix will play into what Microsoft's solution is. Like, if for some reason you've gotta send it in to Microsoft, this might screw up your warranty situation. But, at least you'll have a working Zune sooner, rather than later. If you have the patience of a gnat, we'd recommend you waiting for an official fix. Thanks Neil!