Hmmm ... well, it's complicated.
The current version of Audio::Taglib indeed supports only taglib 1.4, and not very well at that.
I'm working on support for taglib 1.5 based on the
release of Audio::Taglib that was made by the original author. When I'm comfortable with that, I'll release it and go on to taglib 1.6.3 (current Fedora 14 RPM) and then on to taglib 1.7 (sigh!)
A Windows platform would be a big help. Perhaps you can find binaries for 1.6.3 or 1.5?