We have done a lot of these but as a ps engagement. It isn't as much of a migration since you create the vFiler or vserver then add volume resources. With cluster-mode it had to be a vserver though.
I have a list of key things on the physical controller to recreate in the vFiler... Cifs shares, exports, igroups and mappigs, quotas, user mapping, local and domain users and groups, nis, ldap, cifs setup, NetBios aliases, homedirs, and more. A lot of things to consider but you can plan them all and have a very short outage to move resources into a vFiler or vserver
