User blog comment:Mobo85/Rappin' with Phineas and Ferb...and Dan and Swampy and Miss Piggy/@comment-3473686-20110817234900/@comment-3212462-20110818054005

Season 4 can't be at the end of 2011 for two reasons. #1 Because that's not enough time for all the season 3 episodes to air (there's still a lot more to come!), #2 because they apparently haven't even started season 4 yet. It takes several months (even up to a year) for an episode to be completed.