The dates/cast were announced:
Dates: 29-30 of May in Almaty, 1 of June in Astana.
Cast: Mao Asada, Daisuke Takahashi, Carolina Kostner, Evan Lysacek, Brian Joubert, Stéphane Lambiel, Elladj Balde, Tatiana Totmianina/Maxim Marinin, Tatiana Volosozhar/Maxim Trankov, Mirai Nagasu, Nathalie Péchalat/Fabian Bourzat, Joannie Rochette.
Denis was intriguing about it a bit in his Instagram:
More info coming soon.