Update:

I have started writing a plain C++ layer for writing portable VFS 
modules (to be be used in different VFS environmens like KIO, GnomeVfs,...)

At the moment it's just the beginning of an interface proposal. But i am 
sure with your help it could become something useful... :-)

http://www.scheinwelt.at/~norbertf/common-vfs/
http://www.scheinwelt.at/~norbertf/common-vfs/commonvfs_module_041228.tar.gz

Norbert