Copy CiviVolunteer volunteer needs when creating a repeating event
I think you can find all you need about this question at https://issues.civicrm.org/jira/browse/VOL-37

Note also that CiviVolunteer 2.0 beta is planned for a release on September (2015) - https://civicrm.org/blogs/ginkgofjg/civivolunteer-20-whats-in-the-works.