Perhaps this is only a phemenon that I've noticed (or only interests me), but I find it amazing that public broadcast is always on the cutting edge of technology. Here in Pittsburgh, not only is our PBS-HD channel one of the best on the air, but even it's affilliate radio station is one of just a handful in the city brodcasting HD-Radio. Heck, I can't even get FOX in HD where I live right now.
Considering that PBS gets most of it's funding through government programs and fund drives, and without the benefit of advertising, public broadcast has been remarkably on-the-ball. You'd think the other stations would have the resources to make the changes faster. But then again, for the corporate stations money is the bottom line, while for PBS, it's simply making the best product they can.