AMD hasn't offered a new release date beyond next month.
AMD has announced that its Mantle API has been delayed. The patch, originally set for release this month, is now expected in January of 2014. AMD has not offered a more specific release date than 'January 2014,' but it sounds as though the reason for the delay is on the side of BF4 dev, DICE. AMD released a statement on the delay of the Mantle patch for Battlefield 4, the first title to support Mantle. The statement reads as follows:
"After much consideration, the decision was made to delay the Mantle patch for Battlefield 4. AMD continues to support DICE on the public introduction of Mantle, and we are tremendously excited about the coming release for Battlefield 4! We are now targeting a January release and will have more information to share in the New Year."
AMD announced its low-level high performance graphics API back in September. The API allows developers to ‘speak the native language’ of AMD’s Graphics Core Next architecture, which is present in modern AMD GPUs and APUs.