Glad to hear it.
As far as I knew, the standing convention in most of the EU has always been that a series title can be a trademark, but not a film or episode title. Losing that to a new precedent would have been a disaster for the public domain.
Just imagine if the original publisher of a book trademarked the title just before copyright expired: how would the public be able to exploit the now public domain work if they weren't allowed to use the title?
As I understand it, US law, as always, is one stage of weird ahead of us. The original Wizard of Oz book (and Baum's own sequels) is out of copyright, but the world of Oz is a trademark. This means that Baum's books can be distributed for free, but no-one can write new books except the trademark holder.