So we go through all this effort to implement the Dewey Decimal Classification (DDC) system, and now it seems the effort may have been wasted. We've created categories and templates, and all sorts of other pretty things to manage this new system, taking extra precautions to ensure that the system was both usable and expandable. Using categories and DynamicPageLists we were able to create a whole swarm of dynamically-updated lists of books by subject.
Recently en.wikibooks got a whole new namespace to use for organization, and we've been putting it to good use. For a look at the initial work (most of it bot-created) in organizing, you can travel to [[Subject:All Subjects]].
What we have now is (at least the beginnings of) a powerful new system for organizing books: logically arranged, automatically updated, completely uniform. In short, we just don't need DDC anymore, especially not with it's obvious deficiencies in the areas where Wikibooks needs the most precision (computer books).
Beyond that, some questions have come to light about the legality of using the DDC. It is under copyright, although the extent to which it is copyrighted is a matter of some ambiguity. The OCLC website has the following to offer in it's FAQ:
"The DDC is owned by OCLC Online Computer Library Center, Incorporated ("OCLC"). We do consider licensing arrangements for the DDC database. To request a licensing proposal, please send an e-mail message to DeweyLicensing@oclc.org, describing in detail your proposed use of the DDC."
Do we need a license even if we aren't using the database? Do we need a license to apply numbers to books, or do we only need a license to use the categories that OCLC has already created? If the system is a copyvio, we might have to delete it whether we want to keep it or not.