User blog comment:D. Cello/Assassinews 09/23 -- Videos and cinematics/@comment-3235544-20110924030715/@comment-4043223-20110924041427

In all likelihood it is 16 but it hasn't been confirmed... surely in game this person will tell Desmond who he is or "was" (before becoming a part of the Animus and the fabled Subject 16) but until we know more we should be mindful of the wiki policy and standards recommended for sourcing information.