Hola! We are evaluating owncloud, and one feature I would be interested is: if some anycast or similar type distributed storage space option is possible, or planned?
ownCloud itself is storage agnostic, you can use it on any type of POSIX filesystem.
GlusterFS offers NFS exports as far as I can see.
Finally you can also use S3 compatible storage backends for your data, there are many different options out there, however that’s an enterprise only app.