Noch nicht viele Infos, aber es soll im Oktober rauskommen und an Revelations anschließen.
Don't get too excited, as there have been no details revealed whatsoever, but Assassin's Creed III has been officially confirmed by Ubisoft today, complete with an autumn release date in line with the rest of the series.
(...) Assassin's Creed III will be releasing on October 30th, 2012, presumably picking up where Assassin's Creed: Revelations left off, which has also shipped 7 million copies since launch, Ubisoft confirmed.
Xbox360Archievments.org