Just got back from a US trip. One of the hotels I was in (San Francisco Marriott) had 42" (I think) plasma TV's in the room and HD service. Basically ABC, CBS, NBC, Fox, CW and PBS were in HD as well as some satellite channels including HDNet, Universal HD, HBO and ESPN.
Some impressions.
Network channels were superb - really couldn't see much difference between 1080i and 720P (ABC vs say CBS). Watching the World Series baseball on Fox was a revelation - that's the way to watch live sports!
HDNet and Universal HD were lower quality. Their origin is satellite (the network channels I suspect came from cable) and it seemed like the bit rate was compromised and pixellation was obvious. Watched Hunt for Red October and Serenity in HD and it was good but not as good as the network progrmaming (watched on episode of CSI Miami in HD).
ESPN was superb. But they are known for their HD broadcast quality and no compromise approach to HD broadcasts.
I can't wait till we get some HD here
Larry