Boise State is looking to get ouf of paying $5 million to the
Big East American Athletic Conference for not joining their league, and remaining in the Mountain West. The reason behind the lawsuit is that the Big East is not longer sponsoring football, and that the AAC is a completely different organization.
Boise State has a legitimate point in this lawsuit because the conference they intended to sign up for is vastly different, and also the main point is that the Big East is no longer sponsoring football. Reasons to why this lawsuit is valid is because the Big East failed to live up to promises such as retaining BCS status and was not able to add any schools West of the Mississippi River -- let alone the Rocky Mountains.
Another reason that Boise State is filling a lawsuit is that the school caught wind that the AAC would be suing Boise State, and in all likelihood the reason behind suing the Broncos is to get the $5 million they feel is owed to them.
This is not the first time that a team has sued to get out of paying an exit fee, just recently West Virginia negotiated getting out the 27-month waiting period to leave the Big East early and move onto the Big 12.
I am not a lawyer, but the league that Boise State signed up to play for has changed beyond recognition, and the end result will likely be that Boise State will not have to pay anything.