Danwei.org has an interesting article about renewed efforts by China's State Administration of Radio, Film, and Television to purge regional dialects from TV. This presents makers of Communist docudrama with an awkward problem: viewers know perfectly well that revered leaders of the past, including Mao and Deng Xiaoping, didn't speak the pristine Mandarin that actors are now being asked to put in their mouths. Linguistic unity thus requires the glaringly obvious revision of essential moments in Chinese history, as a business editorialist points out.
I can't imagine what it would be like to listen to Chairman Mao stand on the Tian'anmen rostrum and proclaim the founding of the government of the People's Republic of China in a Luo Jing-style standard accent, nor can I think of what Commander Chen Yi's long, drawn out "What?" would turn into in standard Mandarin. Ni Ping even said, "There's a loss in verisimilitude when leaders speak Mandarin," and the actor Lu Qi said, "Without using dialect when playing Deng Xiaoping, it's hard to embody the charm of the great man."