I've been working with Wordpress for years upon years and have found that there is always one thing lacking...a good sports related plugin to create content whether it be for teams (or leagues). I've used online services but have always wanted something to be made for Wordpress because I love the Wordpress system.
I have yet to see something on the wordpress market that is updated frequently and compatible with different sports. Most I've found has been frequently based around European Football.
Throw in a multi-site option to spread your stats and blogs across your leagues teams websites (a lot like I think most sports leagues and systems do) and you have a sure fire winner.
Perhaps the scope of the project is to big but I cant be the only one out there that has been searching high and wide for a plugin like this.