The official Pokémon movie website has updated. Translations follow:
Media Information
Magazines:
Thursday April 19th: "Famitsu" - Presentation of the new Pokémon
Saturday April 21st: "Corocoro Ichiban!" - Presentation of the new Pokémon and characters that appear in the movie, etc.
Saturday April 21st: "Saikyo Jump" - Presentation of the new Pokémon
Saturday April 21st: "Dengeki Nintendo" - Presentation of the new Pokémon
*Note that these are the scheduled publication dates, and as such are subject to change without notice.
Source:
http://www.pokemon-movie.jp/news/?p=3249