"And would it be true if you are using HDMI from the source such as HD cable to 805 and then HDMI to the TV?"

No, it'll simply pass the signal through.  It won't downconvert it.

I see the downconversion as a good thing.  It forces me to upgrade my component video equipment to get HDMI outs.  Nothing like a reason to get the latest and greatest.  :)

Bryan