I've just finished a new version of DokuFS, my FUSE for DokuWiki.
New features are:
A cache (with memory limit)
File size is now set properly (some graphical editors rely on that)
Saving a file without content but a revision comment does no longer directly delete the file, but removes it from the directory listing (deleting the file was irritating some editors)
Saving empty files doesn't change their content, this change was necessary because on an edit an empty file is saved first before the new content is saved.
All in all I have to say that writing a filesystem isn't that easy as I thought when your back-end isn't a traditional storage. The next features that will be implemented are permission-checking on client side and a check if the write was successful.
The filesystem can be found under dokufs.rb, usage information is under DokuFS.