Dragon Ball Super and One Piece are each getting 1-hour specials in October. The one hour One Piece special will air on October 1, while the 1-hour Dragon Ball Super special will air on October 8.
These specials will not be crossovers, instead it seems they will be two episodes from each anime series aired back-to-back. The purpose for this is unclear as the specials air from 9 AM to 10 AM in Japan. That’s the same time One Piece and Dragon Ball Super air in Japan on a normal basis. In other words, there will not be an episode of Dragon Ball Super on the week of the One Piece special and there will not be an episode of One Piece the week of the Dragon Ball Super Special
Shuiesha’s Weekly Shonen Jump magazine has art featuring Goku and Luffy to commemorate the announcement, with a collaborative promotional video scheduled to release this coming Monday.