The one aspect of it that seems useful to me is the receiver's ability to pass through while in standby. As I understand it, this allows you to use your TV's speakers for audio if you prefer (which I often do) instead of external speakers. Right now I have an old Sony WEGA flatscreen tube TV that has good sound. When it eventually gets replaced, I'd like to be able to retain that function in the new TV. If the HDMI connection provides this option (through the Audio Return Channel-ARC), that would be cool. I have some massive Polk tower speakers in my living room that just are not suitable for TV viewing, but are fine for DVD playback.
The power control feature seems convenient as well. My AVR is a Pioneer, who does not make a TV, so finding a compatible display that supports all these features may be a bit tricky. And, speaking of remotes, I just got a Logitech Harmony 300 for the bedroom that works great; there is nothing among the four devices it's programmed for it I can't easily control. When I finally make the jump to 21st century technology in the living room, I'm hoping the Harmony will do what the dedicated remotes for the components can.