I find myself working with ZFS snapshots quite a bit, and as a convenience, I'd prefer if I didn't have to prefix the commands with pfexec. For example:

pfexec zfs rollback rpool/vbox@clean

Fortunately, it is possible to delegate the permission to run ZFS commands to my user account using zfs allow. For example:

pfexec zfs allow bleonard snapshot,rollback,mount rpool/vbox

Note, the ability to 'mount' is required in order to create and rollback snapshots. See the zfs man page for details.

To see the permissions assigned to a file system:

bleonard@opensolaris:~$ zfs allow rpool/vbox
-------------------------------------------------------------
Local+Descendent permissions on (rpool/vbox)
	user bleonard mount,rollback,snapshot
-------------------------------------------------------------

Now rollbacks are a bit easier:

zfs rollback rpool/vbox@clean

You can delegate any of the zfs commands, including allow. For more details see Delegating ZFS Permissions.