She's an addict, she is not going to burn her bridges, she wants to keep her options open... all addicts do that...
It is possible to move on without losing hope.. You move on with your life, but leave the marriage to her to pick up at a later time after the affair runs its course... and it will...
Phil McGraw states quite clearly in his website that the long term success rate for affair couples is less than ONE PERCENT... it will die out on its own... it has little choice...
The question is what kind of man will you be and where will you be when it does end...?