I have never looked at it from the point of view of libraries themselves. I can see how valuable it would be for cataloguing a small library collection, but I wonder how easy it is to export the records - anybody know? You wouldn't want to spend all that time cataloguing your holdings only for LibraryThing to change/merge/fold altogether!
Wenzeler's article was very interesting and I really like the idea of enhancing existing library catalogues with user-generated content from LibraryThing. I believe AquaBrowser, when it comes to Cambridge, will create a shinier, happier user experience anyway though, so do we need LibraryThing?