since some people were interested in using WebDAV together with Twisted recently, I decided to send you my current work on this. I essentially used the "pydav" implementation:
and wrote a twisted extension. Once you are familar with "pydav", the twisted extension is self-explaning. I hope, the short README.txt will help you. By the way, I tested this implementation together with the Windows Explorer and cadaver, a command line WebDAV client.
In my opinion, it would be very useful to integrate WebDAV support in Twisted. Well, since I have never contributed code to twisted, I do not know, how to do this.