New DLC for Dragon Age II is supposed to be announced during Comic Con, according to the game's Twitter account. However, the achievements for the upcoming Legacy DLC have already been listed on Xbox360Achievements.org.
While they don't tell us that much, they do provide a pretty good idea of what we'll be doing in Legacy. Check out the achievements below, unless you want to remain absolutely spoiler-free.
It looks like Hawke will be making a trip to the Vimmark Mountains again, and possibly to the Deep Roads below them. Family Outing's requirement to have your brother or sister in the party might be a problem for some if you already finished it, depending on how you played Dragon Age II.