Yes, Apache VFS does provide a facility for implementing your own file system providers. In short, you need to implement your own version of the FileObject, FileSystem, and FileProvider interfaces.
You can find a good example at the following URL.
http://detailfocused.blogspot.com/2009/06/add-plugin-for-apache-vfs.html
Apache also provides a good number of implementations out of the box, so check the source as well.