While "collection" may not have been an optimal choice, imho "book" is not either. We have Special:ISBN, the subject matter of which are books, and there is work on its way from several groups to add enhanced ways of referencing book sources of articles which may likely end in the additions of a book: namespace, or very similar.
So as not to confuse existing printed books, or other literature, with the subject matter of this extension, I'd suggest a name referring to the "yet to be printed" aspect of extionsion:collection to be more apropriate.
Thanks for listening.
Version: unspecified
Severity: enhancement
URL: http://code.pediapress.com/wiki/ticket/356