Disney wants to own Star Wars, Indiana Jones, and whatever else Lucasfilm owns so that they can market it in their amusement parks and get a bigger cut of the profit. I'm sure that's the main interest. That's why Disney bought Marvel and the Muppets too.
I wonder if the Lucasfilm deal includes Lucasarts games. I could see Disney doing stuff with their game properties like Sam and Max, Maniac Mansion, and Monkey Island.