No, it's for real. She and Pan Yue Ming have already registered their marriage. Dong Jie's parents have already confirmed it and it's been all over the news.
http://ent.163.com/08/0905/05/4L28U1EK00032KMI.html
There's even news that Dong Jie is pregnant.
http://ent.sina.com.cn/x/2008-09-25/03112182400.shtml