Currently, only the owner of a task can alter the queue that it is in. Therefore, a manager or admin must either ask the task owner to make the needed change, or the admin/manager must reassign the task(s) to himself first. If you have altered your process, if you are training someone who has made a mistake, or if you are just working as a team and part of your process includes moving a task between queues, this is all impossible right now unless you are the owner.
I highly recommend opening up this permission, at least to admins.