I think it will be possible, since the iDisk is basically nothing more than a web-disk. It should be possible doing this with any kind of webdisk, as long as it mounts as a ‘normal’ disk in the finder. However, loosing the ability to sync the webdisk to your harddisk would also mean loosing the ability to access your library and papers when not connected to the internet. If I find something, I’ll write about it though.