Nothing is impossible, but it is highly unlikely we'll see dual-layer burns on a 411S/811S.
Pioneer reportedly demo'd an A06 burning dual-layer with nothing but a firmware update at CES, but no details were released. Despite a lot of speculation, they did not say they would release any such firmware upgrade for existing models.
The industry pattern has been to release faster drives with new features as new models with a higher pricetag. Sometimes creative hackers are able to reverse-engineer firmware updates, but in this case most people think the lasers in current drives aren't up to the task.