See article on AsiaOne - http://news.asiaone.com/News/AsiaOne%2BNews/Singapore/Story/A1Story20070909-24742.html
Came out in the news that the government will let some people (chronically sick and those who already have annuity) opt out of the scheme. Good move. Why should I pay for annuity if I am so busy trying to pay for medical bills already??