High School Musical 3: Senior Year hasn't even wrapped filming yet, but Disney is already writing the fourth installment of the series. But don't expect the whole gang to be returning to East High for High School Musical 4 -- new characters will already be introduced for HSM3, and the whole cast may not return for HSM4, according to the Hollywood Reporter.

Ashley Tisdale, for one, has hinted that she's over playing Sharpay. "We love HSM, but we kind of have to move on," she tells Us Weekly. "It will always be a part of us that we loved to do. All of us have gone through so much together, like winning the Billboard award and an Emmy and an American Music Award! That’s something that we’ll always remember!" So what does Ashley want to do? "I'd love to do more romantic comedies in the future," she says, adding that she'd like a career like "Kate Hudson -- she's funny!"

Hey, ya can't hold on to high school forever…