Are Book Genres Being Replaced by Tags?

From io9: Are book genres being replaced by tags? Eric Rosenfield debates whether or not standard genres like 'fantasy' and 'sci fi' (and, one assumes, 'romance') can still be used to classify books when books have been splintered into tiny little niches that potentially cross over into multiple designations. Have an excerpt:

The thing is though, the handful of categories that fiction is still sold under-as classified on Barnes and Noble.com, "Fiction & Literature", "Mystery & Crime", "Science Fiction & Fantasy", "Teens", "Romance", "Horror", "Thrillers", "Westerns" (and lumped in is Poetry which is not fiction, and Graphic Novels which are another medium altogether)-are accidents of history and technology, and even these clear demarkations are of recent vintage; bookstores did not even have separate science fiction, mystery or romance sections until the 1980s or so, and books specifically marketed to niche groups were relegated primarily to book clubs, mail order, specialty stores, and if one was lucky, newsstands, all except the latter being where the modern genre categories really emerged after the implosion of the pulp magazine markets in the 1940s and of the bulk of the science fiction magazines in the 50s. And yet we now take these categories for granted and talk about "transcending" them as if they had such impenetrable physical form that they can only be passed over metaphysically.

The world that gave rise to these categories is fading rapidly into nonexistence. The new bookstores are not circumscribed by retail space, they're the limitless possibilities of a search box. We live in a world in which most any book you can think of can be downloaded to your home, and where anyone with an Internet connection can fill a blog with reviews, interviews, news items, and free-form ramblings about whatever she thinks is important. That is a paradigm shift on a level we don't fully understand yet.

I no longer believe we should stop using terms like science fiction and fantasy and so on; those terms can be useful in describing certain things, certain ways of reading. But their status as hard-and-fast slots into which we plug in all of our books is already starting to fade, as the once nebulous megacategory of science fiction and fantasy splinters into steampunk, urban fantasy, paranormal romance and so on, subcategories that once upon a time might have been merely commented on but which because of the 'Net have blossomed into subcultures all their own, distinct and often non-communicating with the groups reading the space opera or sword and sorcery that since Star Wars and the Lord of the Rings have dominated science fiction and fantasy respectively.

It is a big excerpt.