Today I found Sardine – a nice library which aims to be an easy-to-use Java tool to send WebDAV requests and process the replies. I especially like the ellegant use of JAXB.
It's still under developement, so don't expect it to be production-ready (e.g. I found a deadlock in a simple use case). But it's alive and hopefully some community will gather around it.
It's not mavenized, but I am going to create a maven artifacts time by time and publish them in the project's SVN.