User blog comment:Bronzey/Tying up the threads: possible storylines of Mass Effect 3/@comment-730941-20100328081324

If they're using the same facial customisation tools as they did for ME and ME2 (where the face you imported looked the same), it probably will be set relatively shortly after the end of ME2 (like a few months). It would be extremely hard to 'age' an imported Shepard's face and might turn players off their own character.