SKOS in Topic Maps

I've mentioned here a while ago the new blog of Lars Marius Garshol. His last post is about using SKOS vocabulary in Topic Maps, and is presented as a long overdue school work. Well done.
Now the crucial question is maybe not how you can do it (something Lars Marius shows quite neatly as usual), but why one would want to do that. Adding a real world use case would be cool ...