Even though companies are saying that the U.K.'s CD singles sales are down, looking at those numbers suggests that they are probably the best in the world. Even during the non-holiday season, top singles sell tens of thousands of copies in their first week.
In the U.S., it takes 500,000 copies for a single to go Gold. Yet, often the top singles may sell just mere thousands!! Downloading and regular CD sales have all but eliminated the CD single. Even as far back as the mid-90's, the CD single market was dropping. Music fans just didn't want to pay $5+ for a CD single of a song with a bunch of remixes or songs they don't really want. This is why downloading - legal or illegal - took off. One can get just the song one wants and at a far better price! I'm so happy iTunes is keeping prices at $0.99 (in the U.S.). There's no way a song should cost more than that! There's no packaging, no physical item and just one song (unlike years ago when there was a record, a sleeve and b-sides).
Once the U.K. singles market "dries up" (if that happens), then that's it. We may never see another CD single again! Those b-sides are remixes will be a thing of the past. Artists may release them as special "bonuses" on iTunes or whatever, but the day of looking forward to getting a new U2 song on the CD single release will be gone. Who knows - it could happen by the time U2 release their next album!