Anora rules as Queen

Another possibility of the Landsmeet is that you strip all power from Loghain and allow his daughter to continue to serve as Queen.

Queen Anora

This may occur if Anora objects to marry either the player or Alistair for whatever reason.  The player also has a lengthy interaction with Anora before the landsmeet.  Interaction with her there will determine her willingness to accept a king.  This outcome puts the player at a great disadvantage, as the player will have little to no power over Ferelden in the days following the Landsmeet.

Also, having Anora be Queen will result in either one of two things for Alistair, his execution or the relinquishment of his birthright.  After Loghain's defeat, Anora still feels threatened by Alistair's right to the throne, so she will deal with it in one of those two ways, her decision of which can be influenced by the Warden's decisions.