The Theater Edition of Pocket Monsters Diamond & Pearl Giratina and the Sky's Bouquet: Sheimi will be released on July 19, 2008 in Japan. Advanced ticket holders have the chance to get a Level 100 Regigigas. Further information about the moves that this Regigigas has will be announce mid-April.

Regigigas is a Pokemon introduced in Generation IV that is the master of Hoenn's legendary golems. Normally, Regigigas comes to life only when Regirock, Regice and Registeel are gathered. Therefore, it requires the three to be in the player's party to awaken it within Snowpoint Temple, where it sleeps. It still appears on the map if they are absent.

In order to receive this Regigigas, you require: a Nintendo DS or a DSLite, and copy of Pocket Monsters Diamond or Pocket Monsters Pearl. Only one Regigigas will be allowed per ticket. You cannot receive it with an overseas edition (Pokemon Diamond or Pearl).

Source: http://www.pokemon.co.jp