The Semantic Web Best Practices and Deployment Working Group has published:
"A Survey of RDF/Topic Maps Interoperability Proposals"
Editors include giants from the Topic Map world, such as Steve Pepper and Lars Marius Garshol.
I still think Topic Maps have tremendous potential, and I wish there was more adoption of them. I tried to set up a Topic Map for the Sun System Handbook, while I was at Sun, but couldn't get approval to publish and set it up as a navigation mechanism for the Handbook.
It's definitely an interesting read, especially section 4.3 on Semantic mapping issues. Lars Marius Garshol has done tremendous work in this area, and the Ontopia Knowledge Suite has some incredible features for viewing/interacting with Topic Maps.