New single-player content for Assassin's Creed Revelations which expands the story of modern day protagonist Desmond looks set to be released after new Achievements for the add-on were spotted by X360A.
The Achievements mention block-based platforming, which all but confirms Desmond stages.
In what could be related, GAME and South African retailer AWX have each listed the Assassin's Creed Revelations: Ottoman Edition. The GAME listing has since been removed, but featured a March 16 release date and the cover mentioned "free downloadable content".
Last year's Assassin's Creed Brotherhood Game of the Year Edition featured bundled DLC so we expect something similar to happen with Ottoman Edition.
Expect an official announcement from Ubisoft pretty soon.
Assassin's Creed III is expected to be released late this year.