Bookcase 0.6.3 adds a Spanish translation and an updated Norwegian one. One new feature is that the column view remembers the previous sort, and uses that for sorted books with the same current sort key. In other words, if you sort first by Series Number and then by Series, books in the same series are sorted by series number, rather than randomly like Qt normally does.
Minor bugfixes include making the expand/collapse all actions work, updating the edit widget after a field category is modified, updating the group count when adding a new book, and making the name prefixes match on word boundaries