User blog comment:Soneas/What will be different in Season 4?/@comment-4989362-20130216061402

actually sometime there will be another 2nd dimension episode, there will be a phinabella episode next summer, there will be an episdoe with phineas gets mad at isabella on season 4 epissode 23, sometime in the future isabella will ask candace for relasionship advice, and phineas and ferb will have a cross over with marvel universe. i got this infor from the creators of phineas and ferb on twitter and interviews.