I don't know if other TV models offer this feature, but the 5.1 signal is available from the tuner only through the optical port.
I'm not aware of pass-through being available in any model for 2010 or prior.
I am in the market for a Samsung HDTV, but I want to be able to get 5.1 Dolby from the digital audio out port no matter what the input. The discussion I have seen seems to indicate that many models of Samsung seem to be restricted in this ability. Is there any model I can buy that will allow me to do this?