We visited Shanghai and Beijing last year, and really enjoyed the experience, I would recommend it to anyone.
The person who was showing us around Shanghai has lived in Hong Kong for many years, and travels frequently on the mainland. He was saying that there has been somewhat of a loosening of censorship in the big cities, allowing a more sophisticated segment of the population to "blow off steam."
Where they are tighter, according to Chris is in the rural areas, where education levels are typically lower and, ostensibly, propaganda and control of information are more effective and yet vulnerable at the same time.
In any event, it will be very interesting to see how this plays out.