This article says that they are. More importantly, it says that people do not care as much about their music or the quality of their music-listening experience as much as they once did. That's very interesting if true. I wonder if this is a permanent trend or if it is temporary. Beyond a certain point, the average person definitely does not care about the quality of their sound. How else can we explain the explosive growth of low-bitrate MP3s? They are moving to higher bitrates now, but when the Diamond Rio had 32 megs of RAM, people weren't listening to 192kbps tracks. The list of high-quality audio formats built to replace the CD is long. The list of failed products is equally long. DVD-Audio? SACD? DCC? DTS CDs? None made more than a blip on the radar.
Of course, quality audio for music may be declining, but people are paying more attention to the audio in their home theaters now.