By decree all HDMI input to the HDTV shall not pass more than stereo. This is not a Samsung issue or decision.
My Fiance bought me the Vizio 5.1 soundbar for Christmas to go with our UN46C6300SF HDTV. I connected it to the TV using the optical cable, but only the bar and subwoofer work, the satellite speakers produce no sound. I know that the speakers themselves work as I have a Bluray player connected separately to the soundbar and everything functions fine.