I hope your planning is well underway. You haven’t had much time but you will have the chance to develop your skills especially for your speaking exam. You can see a tape of sections of the South China Morning Post final debate from earlier this year (only one side of the case!) : http://www.youtube.com/watch?v=jhhwk0rOQtg. These students have had more time to research their topic and prepare their speeches. You may still get some ideas about using evidence and how to present your case.
While this may be the occasional topic for writing or discussion tasks at Form 6 and 7, the true sadness of the situation only came across to me when I looked at the Prospect journal (link below). The woman in nursing home talking about some of the people in her care highlights some of the hidden difficulties the elderly face as they become more fragile.