Are you talking about the list at the very top of the page from 12-19-2006?
If you look here:
It looks either the same or slightly better.
More telling, I think, is how the stations seem to have all given up telling anyone about HDRadio on their websites. Go to a random radio station's website and look for HDRadio. There used to be a mention of it, maybe 7-10 years back, at the top in the banner area and 5+ years back it seemed to move to the bottom as an annotation.. Like in the "About us / Contact us" section. I think that over the last 5 or so years that they just gave up on telling anyone about it.
The average person on the street still doesn't know what HDRadio is. Your average best answer is, "Isn't that satellite?"
The odd thing is that they know what satellite radio is.
Add to this that HDRadio still isn't all that prominent in cars - at least from when I rent them. I think I've had one car with HDRadio. I've had plenty with satellite radio.
I gave up on HDRadio, at least in my vehicle, back in 2008. It was crappy then and, oddly, you got better receptions outside the perimeter in Atlanta than inside. Inside it'd cut in and out (analog to digital and back) and was quite annoying. I've heard that they've bumped up the power since then so maybe that corrected it.
On top of that, if you want clear, uninterrupted audio from your favorite radio station it's easier to just stream it to your car stereo. I've had plenty of rental cars with bluetooth and over the last few years they even would get the data along with the audio so you'd see things like station, artist, song title, etc. Very cool.
By 2010 HDRadio should have been standard in every radio. If you bought an odd clock radio from Walmart it should have had the HDRadio bit in it. If you bought a new car, even with the base stereo, it should have had HDRadio. It should be as ubiquitous as AM/FM. If someone were to hand you any random radio you'd expect AM/FM to be there. By now, if HDRadio were successful, you ought to have the same expectation for HDRadio being built-in.
I think it was all poorly managed and missed the boat.
Some stations have dropped HDRadio. 95.5 (WSB Talk) used to be The Beat and had the sub channels.. When they went with just being talk they actually made a decision to drop it and I don't think it hurt them.
The odd thing is that HDRadio worked really well in the home. I have a receiver and a few tabletops with HDRadio and, because the antenna was stationary, it just worked great. Nice and clear. Again, you can just stream these stations now and send them to your receiver via bluetooth so it still calls into question the need for HDRadio in the home.. Aside from the fact that tabletop radios with HDRadio in them are really hard to come by, now, and, if you do a search on something like Crutchfield, you'll find that HDRadio is only included in the really high-end receivers ($1000+).
Some of the aftermarket radios for cars come with HDRadio but, again, you have to specifically look for it. It's not just automatically there.
It kind of sucks because I liked the idea of HDRadio but the management of it and implementation of it has just sucked the entire time.