Surround sound pre amps and HDTV

What do I need to know when considering surround sound pre amps to go with my HDTV system? I have noticed that some manufacturer's, such as Parasound, offer an up grade for HDTV. Some talk about "HDTV pass through", etc. At the risk of sounding stupid, can someone fill me in on what needs to be considered for HDTV in a home theater system.
Most pre/pro's will degrade video, If you feel you need to run your video through your pre/pro then you will need to make sure yours does not. Other than that, everything else is audio related.
One less button to press. Basically when you run everything into the preamp(audio/video) and say you switch from TV/DVD the preamp will switch video going into your TV.

If you don't do this you need to switch the input on your TV.

Generally speaking running straight into your TV and switching the old fashion way will result in a better picture. Most are claiming a no loss pass thru, but you know....

If you really hate pressing buttons consider a remote with macro functions you can program. I have one of these, still need to program it..:)