I've been watching The Simpsons for many years now and I was looking forward to their big screen debut. I was not disappointed! It's very funny. It's like a big episode (bigger size and duration), but I didn't mind paying money to see it, because, well, it's a movie!
And I'm sure there will be more. First, it is very strongly hinted near the end of the movie. The real end, that is, the one after the end-credits start scrolling. There's plenty of little bits during the credits, so if you're the type that leaves as soon as the credits starts, you will not see the whole movie. D'oh! Second, it's making a ton of money.
The short version of the story is: Homer makes a big mistake, the whole family gets in trouble, Homer takes it upon himself to fix his mistake and against all odds, he succeeds! I hope I didn't spoil it for you... ;-)
To be seen by all Simpsons fans!