Your sentiments are exactly the same as most Zhu Xian fans. Yu Zheng has asked for suggestions on his blog for who to be cast for the leads. Most people are voting for Hu Ge as Zhang Xiao Fan, Tang Yan or Liu Shi Shi/Liu Yifei as Lu Xue Qi and Yang Mi as Bi Yao. As YM received many votes to play BY (plus the fact that she's currently working with Yu Zheng on set), he was able to discuss with her and cast her in the role. Nonetheless, this is not final and YM has yet to sign a contract which confirms her participation in his next film.