This will effect the Sounders the least of all of Paul Allen's Vulcan Sports empire (Seahawks, Trailblazers, Sounders), and will likely mean that Gary Wright has a little more weight in the business decisions for the team.
Here's coverage from the teams associated with this move;
Tampa Bay Lightning get new CEO and minority owner
Seahawks head leaves; in a while
Blazer's fans react
Here's Sigi on the change
(On Tod Leiweke announcing resignation . . .) "Obviously Adrian [Hanauer] has worked with Tod a lot longer than I have but in the year and a half I have been here I have grown very fond of Tod and he is a friend. Not only is he sort of my boss, along with a few other bosses I have, but he is definitely a friend. He is somebody who has been tremendous for our organization, especially the way he has treated the Sounders and the whole Seahawks and Sounders organization, the respect that was given to the Sounders right from the beginning, I think that comes from the top. I think for sure we are going to miss Tod because he is a great person, a great individual and a tremendous leader. We wish him well with his opportunity. I know he wouldn’t have left unless it was something that was a great opportunity for him. I know he loves his hockey so that was maybe a little bit of an influence there. But he is a great person and we are certainly going to miss him with our organization. We are going to miss him in Seattle."
Tod was a huge part of why the Sounders were treated like a partner by the Seahawks. It will be interesting to see how the two organizations interact now.