I did buy this bracket off Ebay thinking I'd be able to turn my desktop into a 5.1 Dolby receiver. On Windows 7, however, so far I can only achieve stereo using optical-in. If anyone knows whether this is a limitation of the chipset, driver, or software, please reply and message me. I hope it was worth ~$20 for this experiment.
(My specific board is Gigabyte GA-MA790X-UD4P)