This story wasn't supposed to be about 'cover mount' CDs per se (the CD with The Wire is only available to subscribers), but there's a related article on this topic in The Guardian today. Uncannily it also uses the term "an embarrassment of riches" in the first paragraph.

Thanks again to Five Eight for this link.

And now, possibly for a limited period only, you can get Five Eight's report on covermount CDs free of charge from their shop.