"[The Simpsons Movie] took us four years [to make] and it killed us," said Simpsons creator Matt Groening, who was taking part in a keynote Q&A on Saturday with longtime Simpsons producer David Silverman at UCLA's annual entertainment symposium. Groening went on to state that the feature film "stole animators" and drained resources from the TV series, while Silverman added not to expect another movie for "maybe another 10,15 years" - meaning the show would be approaching its 40th (!) season, should it manage to survive for that long.
After floating about the idea of a feature film from early on in the show's run, The Simpsons Movie first went into development in 2001, with the screenplay going through more than 100 rewrites before animation work commenced in 2006. The film finally hit screens in July 2007 and went on to gross over $527 million at the global box office, not to mention untold riches in licensing and merchandise.