Steve jobbs had a huge number of shares due to the Pixar takeover, as he helped fund Pixar.
Maybe Apple will buy into Disney as Apple seem to want to buy something at the moment, the have also been linked to buying a car racing team in the uk.
Would it change much if they did? Probably not but maybe their products would appear in even more films than they currently do. Every Pixar film where a phone or computer is used its always Apple.