An exciting milestone has been reached in ZFS land. Mark Shellenbaum has just checked into the Nevada gate some bits that will allow non-root users to have access to zfs. The short version: with two new zfs subcommands, 'allow' and 'unallow', a sysadmin can grant specific permissions to users (taking snapshots, setting properties, &c). The long version: see Mark's blog entry I just linked to.