Have fun in China! I was there several years before Olympic and it was most memorable experience of my life. China was my true starting point of my 6 month SEA trips and I would definitely would like to visit again one day. Be careful in Xian, I have heard and witnessed many cases of petty thieves.
I don't know how things are post Olympic but when I was there NOT a single word of english in any of the menus. So basically I was finger picking some items on the menus with mifan or chowfan. Most turned out good but few days I had mistery meats/fish/??? with rice and beer. Then again I was on backpacking trip so it could be different for hlywud