I subscribe to the First Look podcast on my iPod Touch, and I can't agree more with this request. Can't believe it's been 6.5 years and no one else has complained. When each video starts, the first thing I have to reach for is my volume rocker. Turn it up or turn it down, each video has its own volume level. And the intro music that jumps in sometimes screams at me like the volume in a late-night TV commercial.
I was enjoying some CNET TV, and some of the videos sound like they are recorded at like +10dB over others. Very unpleasent suprise to suddenly have someone screaming at you about an HDTV. o_0