Ever since multiplayer was introduced into the Assassin's Creed universe, most of the franchise's DLC has come in the form of multiplayer perks, such as characters and map packs. The DLC for Assassin's Creed: Revelations has thus far fallen in the same suit. But it appears that some single-player DLC for ACR is on the way.
Xbox360Achievements picked up on 10 new Achievements that popped up without warning for ACR. One of the Achievements involves crossing the River Styx, and another requires Ezio to fall 25 meters and land on a block—that has to be the most oddly specific Achievement in existence. As these Achievements don't follow the single-player campaign, and they're too specific for multiplayer, it makes sense to speculate that they are tied to some other single-player DLC forthcoming.
Even though this is pretty much pure speculation, especially since Ubisoft hasn't confirmed or denied the DLC, more supporting evidence for the rumor come from the upcoming Ottoman Edition of ACR. This new edition of ACR seems to be a "Game of the Year" edition, and it claims to include "unnamed free downloadable content."
Still think it's speculation? Either way, would you prefer single-player DLC over the usual map and character packs?