I stumbled upon this piece by Frank Dai, and find the description of the mechanics of self-censorship to be equally entertaining and explicable:

All the staff at the Chinese bureaucratical institutions tend to think one thing first before they did anything else: how their bosses will consider? They were always trying to figure out the bottom line of their boss because they worried about exceeding the limit of tolerance. Moreover, the bottom line is often underestimated by these staff. To put more bluntly, they scared themselves. Let's look at an example how the people at CCTV works: If we set the tolerance rate at 10 for President Hu, the rate for the Ministry of Propaganda would be degraded to 9; 8 for the Ministry of Broadcasting and 7 or 6 for the officials at CCTV. When comes to the program producers it would be a miracle if the rate stays at 2 or 3. How can a TV program be excellent with such bottom line principles?
It's as simple as it's genious, and it's a way of things we should all watch out for. Not least in these Wikileakin' days...