The movie has been on low profile because the company in charge [Chuan Qiu Hong] hasn't wanted anyone to know much about the movie, or about the secret cast. Yesterday though SinaEnt got in the secret interview and was able to confirm that the directors table will be filled with director Zhang Yi Mo and Tian Zhuang Zhuang and so on. In the actors section the leads will be Fan Bing Bing, and Leon Lai Ming; Both actors of high statuses may have been one reason why the movie decided to keep a low profile. Both actors will be acting as Yang Gui Fei and Tang Ming Huang respectively. Other than these two though the cast also includes, Chen Zhong, Wu Gang, Yu Jing, "Wu Zun" and other actors/actresses.
It is confirmed that the great love story of Tang Ming Huang and Yang Gui Fei has ungone much work and now has hit perfection, it has taken a long time to confirm the cast though because perfection was the idea behind the movie. This love story and character of Yang Gui Fei was made in favor of Fan Bing Bing and she was moved to tears by the script so they have confirmed that the cast will wait for Fan Bing Bing's schedule.
So far I've checked and 2015 is the only confirmed time, but we will see.
As for Wu Chun's character nothing has been confirmed but when time comes all will speak!!
credit to sinaEnt.