They are 767 replacements, but could also launch new routes where a 200 seat aircraft would do better than a larger capacity plane. The 787 will have longer range than any 767. However, AC has not given any hints as to where they will fly the first aircraft. Since AC's 763's will have the new J product and new seats with IFE in Y, too, there won't be a significant revenue gain on any particular route. The benefit will be almost entirely on the cost side, and it's huge, so that benefit would be picked up on any long-haul route where a 787 replaces a 763.