A physical release will be available at participating retailers and the Square Enix Store starting August 27.
Here is an overview of the collection, via Square Enix:
Collection of Mana ushers players into the enchanting world of the Mana series with the first three titles, Final Fantasy Adventure, Secret of Mana, and the first-time availability in the west of the highly requested classic release of the original Trials of Mana. The three game compilation now includes a convenient quick save feature, and allows players to adventure with friends through a local multiplayer mode in both Secret of Mana (up to three players) and Trials of Mana (up to two players).
Watch the announcement trailer below. View a set of screenshots at the gallery.