They have a major movie coming out every month. It would be theatrical suicide to release more than one movie a month. Unless the only Disney movie released in May is an action film, and they want something more kid friendly. But the reason they usually put Pixar films in June is to get theirs in after Dreamworks' film is out a while. Unless they managed to give this a key early May slot before then... otherwise, there's no logical place to put the film in summer where it'll do the best it can do. Late July is as good as anytime to release it, but Phineas and Ferb's got that slot. It's not merely speculating, it's rationalization to think it would get the last month of the season. No way would they want the film to go directly head to head with the May Marvel, June Pixar, and July Phineas and Ferb slots. That's just common business sense. Above all, there is nothing wrong with waiting a year to get a proper, more thought out release date. Heck... didn't they project the last film to come out some time in 2010, but they were working on the script longer than they thought they would? 2013 is a shooting goal, but things can and might change.