Don't want to turn this into a trip report, but seems a little late for that! China may not be for everyone. That said, the big cities as Beijing and Shanghai are truely big cities. Excellent and reasonably priced dining at a variety of types of restaurants and regional cuisines. Great shopping at name brand stores and lots of markets where you can bargain for $2 fake Raybans and so on. Then, of course there are the sites as the Forbidden City, the Bund, the Great Wall and so on. You can hire a car and driver for $60, so things are reasonably priced.

Certainly in Beijing they are getting ready for the Olympics and they are trying very hard to make tourists feel very welcome. Many places are being renovated. People are trying to learn English. The taxis all have meters that drivers are obliged to use. Overall, it is very safe. So, it is an excellent time to visit China. I found this website helpful and got a lot of answers. www.thatsbj.com For Shanghai it is www.thatssh.com

On the other hand if you want to get into the rural areas the contrast might be quite different from the big cities, but I am sure it would be very interesting.

With respect to being bumped. During our layovers at Narita there were a lot of announcements about overbooked NW flights. This makes me think it is pretty common. I seem to recall on the announcements they were offering $400 travel vouchers. I suspect that could be negotiated depending on the conditions. Unfortunately, none of our flights was overbooked.