Yes, the optical cable will feed the sound back to the HT. Stereo outputs may do the same, if you have them, but are analogue only.
If the TV and HT have Anynet+, you should be able to switch from TV to HT speakers through the TV menus.
recently purchased a Samsung LCD Series 5 530 and home theatre HT-TZ425. They both work great with DVDs. Get quality sound from the Home Theater. Problem arises when i watch standard cable on my TV(DishTV India). It is connected through the AV port present on the back of the TV and the video is fine but the only audio output received is from the TV Speakers. Tried all i could but couldn't find a way to get audio output from the HomeTheatres Speakers.
the other problem is when i try to play HD videos through the USB port available with the HomeTheatre's DVD player. All standard video formats are supported but when i tried to play a 720p movie it said that the resolution exceeds 800x600. Tried the same with the TV's USB interface and it worked!! but as stated before i get audio only from the Tv's speakers when i do this. I read some posts and people suggested using the optical audio ports. will this solve my problem.
Thanks a million.