There may have been confusion over the term “preinstall/bundle”, but both MIIT and the software maker have clarified this point as early as 6/10, that what is distributed is the setup file, and users are not required to install or run Green Dam (IMHO unfortunately ignored by the media at large, who seem to have opted for sensationalism):

a) http://www.taizhou.gov.cn/art/2009/6/10/art_76_36883.html
据新华社电 昨日，工信部有关负责人说
According to Xinhua wire yesterday [6/09], relevant MIIT leader said
…
这位负责人还表示，“绿坝”产品的有效识别率超过90%。考虑到不同层次用户的实际情况，“绿坝”软件运行环境对计算机配置要求低于目前市场主流产品，***并可由用户自行选择安装与否***，同时对用户上网行为不进行任何监控，也不搜集任何用户信息。
The ***end user can freely choose to install or not*** quote from MIIT offical is emphasized.

b) http://www.hngybz.gov.cn/news2.aspx?hyid=82644
绿坝预装只提供安装文件 用户可决定是否安装 – Green Dam “bundle/preinstall” only provide installation articles, end users decide install or not
工信部要求预装进电脑的只是一个软件安装文件，所以用户可以选择是否把它装进自己的电脑里让他运行 – MIIT asks “bundle/preinstall” on computer is only the installation, so end users can choose wheither to execute it to install on their own computer

c) http://news.qq.com/a/20090610/000087.htm
“工信部：上网过滤软件不监控网民 不强制安装”
MIIT: Online Filtering Sowftware Will Not Monitor Citizen, Will Not Force Installation (quote from software maker on MIIT mandate)