Romanian online resource Lab501.ro published intervyus one of the managers of AMD Devon Nekechukom. During the interview, Devon Nekechuk said that about the second half of November, will announce several game engines that will support the new interface Mantle. These engines must demonstrate an unsurpassed level of performance of a new family of graphics cards AMD, with the support of API Mantle.
So it's not just Frostbite 3 that will support Mantle, but there will be several more game engines that will support Mantle. Can't wait for the announcement.
Please do CryEngine 3 and Dunia Engine 2!!!