Alternatively you can locate your MD behind the TV and do the switching by controlling the TV's input via RS232. You then need more cables because you still need to get the audio signals back from the MD/TV to the AV Amp and you still need to control the AV amp too so an additional rs232 control capability is needed. All in all this is messier to be honest.
Thank you for taking the time to put together such a detailed response.
You mentioned an AV amp in each option. Since it's not going to be used as a theater setup, I was planning on using the TV's internal speakers. If I only need a MD in this setup (since I don't use cable boxes and I don't need a DVD), are there good VESA mount options that would just be between the mount and the TV?
The TV doesn't have an RS232 input. Can I control it using USB? It has two USB inputs. Or do I need to use IrDA from the MD?
* The other approach is to locate all of the system equipment centrally at the 'Hub' of the system and use HDMI-CAT5 baluns to transmit the video (and possibly audio) to the TV screens in each room. You will also in this type of system need to have long speaker cables run to each room from the 'Hub' and possibly long rs232 or in-room IP based rs232 controllers - either of which will require more CAT5 to be run to each room. The advantage of this topology is that everything is out of the room apart from the TV & the speaker systems and so there is zero clutter, all cables can be neatly run in-wall/ceiling and there is no issue of fan noise or other 'noise' from the system components as they are all remote from the room.
My system (what little of it there is so far) is actually just a hybrid core in the basement. I have wired the home with Cat6 and there are speakers wires going from the core to in-wall speakers in the Living and Family rooms. So far all we have used the system is for zWave (over 20 devices) and playing audio/Pandora to the in-wall speakers. I'm anxious to get MythTV part working within LMCE so can decommission my standalone Mythbuntu and cleanup the gnarly setup we have in the master bedroom (so far the only TV in the home)
The setup I'm trying to get done will likely be a 32" or 40" TV on a wall in the family room. Ideally, it would go on the wall facing towards the family room from the kitchen and would be able to extend out and turn 180 degrees to face into the kitchen. If I pull that one off, my wife will be REALLY happy.