To add to the information (or confusion, if you prefer), the favicon has returned for me as well. It can easily be explained by the intervention of the New Year god. Or is it related to the fiscal cliff? 
Jon
macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365
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